Underwater station

Underwater laboratory Helgoland in the Nautineum Stralsund (2012)

An underwater station or an underwater laboratory ( UWL for short ), also an underwater habitat , is an underwater diving and work station that is usually built on the sea floor for research purposes such as oceanographic tasks, either permanently or for a longer period of time.

In the 1960s and 70s, underwater stations were used to research, in particular, offshore diving technology and saturation diving , and new knowledge was gained in zoology . The stations remained at the specified depth during the research contract, the supply was ensured by ships or from land.

According to aquanautics, the research area of oceanography that deals with the stationing of people underwater, crew members of an underwater station are called aquanauts .

history

The early history of underwater stations is identical to that of diving bells and caissons . In addition, since long stays in environments with increased pressure (hyperbaric environments) necessarily involve saturation of the body with the surrounding gas, it is also closely related to the development of saturation diving .

The sparkling inspiration that led to the construction of many different underwater stations came from George F. Bond , who between 1957 and 1963 researched the medical effects of organisms in a saturated state in his project Genesis in five phases.

Motivated by these experiments, Edwin A. Link began the Man-in-the-Sea program even before George F. Bond conducted the human experiments in 1962. To this end, he developed a diving chamber in which he carried out various experiments before Robert Sténuit spent just over 24 hours at a depth of 61 m under the name Man-in-the-Sea I.

Also motivated by the results of George F. Bond, Jacques-Yves Cousteau's first Conshelf project took place in France in 1962 at a depth of 10 m. Two divers spent a week in a horizontal steel cylinder.

Now the projects became more demanding. Cousteau's Conshelf II project followed in 1963 . The focus was not only on gaining technical knowledge, but also on the intention to create a homely environment instead of a pure shelter. Five people lived at a depth of 11 m for four weeks, two more for a week at a depth of 25 m.

In June 1964, Robert Sténuit and Jon Lindbergh spent 49 hours at a depth of 126 meters in Edwin A. Link's Man-in-the-Sea II program. The habitat consisted of an elastic balloon called SPID . Analogous to the race to the moon , a race for leadership in stationing people on the sea floor began. The systems became larger and the depth of use was expanded.

A number of challenging underwater stations followed, in which people stayed for several weeks and at great depths. With Sealab II , the largest habitat was created with a usable area of 63 sqm, which was used at a depth of about 60 m. Several countries built their own stations almost at the same time and began experiments mostly in shallow waters, while new records were being broken. In Conshelf III, six aquanauts lived for several weeks at a depth of 100 m. In Germany, the UWL Helgoland was the first habitat to be built for operation in cold waters; the Tektite stations were more spacious and technically more sophisticated. Probably the most ambitious project was Sealab III , a conversion of Sealab II , which should now be operated on 186 m. When one of the divers had a fatal accident due to human error while still in the preparation phase, all other US Navy projects were terminated. A French diving company was Janus II , carried out in September 1970 , during which three aquanauts spent eight days in the Gulf of Ajaccio at a depth of 255 meters, a new record, as no one had worked so long under such a high water column up to that point.

Internationally it should be noted that all major projects started except for the La Chalupa habitat were carried out but not continued, so that the following habitats were smaller and designed for shallower depths. The race for greater depths, longer missions and technical developments seemed to have come to an end.

For reasons such as lack of mobility, self-sufficiency that cannot be guaranteed, shifting the focus to space travel and / or the transition to surface-based oil platforms, interest in underwater stations fell, so that after 1970 there was a noticeable decrease in large projects. In the mid-eighties, the Aquarius Habitat was built in the style of Sealab and Helgoland and is still in operation today. The first generation of underwater stations ended with him.

The following quote from the Cousteau Society expresses the result of the entire first generation of underwater stations:

" Conshelf proved that human beings can live under the sea for long periods of time but that, even though they have the physical and psychological capabilities, humans are not made to exist in a world without sun. "

“ Conshelf proved that humans can live on the ocean floor for extended periods of time, but while they have the physical and psychological capacity to do so, they are not designed to exist in a sunless world. "

Projects followed that placed experience in the foreground. This is how futuristic concepts for underwater villages and luxury hotels ( Village Sous-Marin, Hydropolis, Poseidon Resort ) emerged. The underwater world was also discovered as a platform for TV game shows ( Progetto Abissi ), underwater observatories ( Coral World / Eilat ) and restaurants that could be reached by corridor from the surface of the water ( Red Sea Star , Ithaa ) or research stations were built the water surface and should have an underwater area ( SeaOrbiter ).

Most of these new major projects such as Hydropolis , Poseidon Resort and SeaOrbiter have not yet been implemented, although the architect of both SeaOrbiter , Jacques Rougerie , and that of Poseidon Undersea Resort , L. Bruce Jones, are known for the successful realization of large submarine projects. However, they clearly show the direction in which future projects will develop.

technical basics

Types

Deriving from the list of previous underwater stations below, underwater stations can be divided into different types depending on the planned depth and mobility. This shows that underwater stations cannot always be clearly differentiated conceptually from diving boats, diving bells or ships. A submersible boat that can be lowered to the sea floor and is equipped with exit locks can therefore be categorized as an underwater station. The same applies to diving bells, which have a dry area and allow the divers to fully emerge. Or ships that have an area in the hull whose pressure can be adapted to the environment and which allows divers to exit via locks. G. Haux wrote about this dilemma in 1970:

“ At this point it must also be said that it is not very easy to narrow down the term 'underwater laboratory'. One could argue about whether Link's diving chamber, which was used in the 'Man-in-Sea' project, can be called UWL. But even the 'Bentos-300' planned by the Soviets cannot be easily classified as it has a certain degree of self-maneuverability. Therefore, there is definitely the possibility that this diving body will be classified as a diving boat elsewhere. Well - a certain generosity can't hurt here. "

The main distinctions are as follows:

Floating	Floating The actual station is located in the hull of a floating structure and therefore constantly under the water surface. In the Sea Orbiter example , this area should extend to a depth of 30 m. The advantage of this type is mobility.
by corridor	Via surface corridor The station can be reached via a corridor to the water surface. This means that the depth of use is very limited. However, the internal pressure of 1 bar can be maintained so that visitors do not have to go through any decompression procedures. This type is generally used on coasts such as B. the underwater restaurant Ithaa in the Maldives or Red Sea Star in Eilat / Israel.
Semi-self-sufficient	Semi-self-sufficient Stations of this type can only be reached by diving, but receive energy and breathing gas through a supply line (umbilical = umbilical cord). Most stations are of this type, such as B. Aquarius (laboratory) , Sealab I and II and Helgoland
Self-sufficient	Self-sufficient The station has its own reserves of energy and breathing gas and is inevitably able to maneuver itself (at least in the vertical direction) due to its self-sufficiency. This type is therefore similar to diving boats or armored suits, but avoids the "complete environmental separation" due to its exit option. Examples are Conshelf III or Bentos-300

The two types of internal pressure: ambient pressure versus surface pressure

With regard to the internal pressure, two types of underwater stations can be distinguished:

• Open station : Almost all underwater stations are set up in such a way that there is ambient pressure in them or slightly above, which corresponds to the principle of a diving bell . The facility has an exit (see Moonpool ) at the bottom through which divers can get in and out. As soon as the aquanauts are saturated with the breathing gas (see saturation diving ), they can stay in the station indefinitely. At the end of a mission, there is then a need for a considerable decompression procedure, depending on the depth of the operation. For this purpose, the divers are either transported with a capsule to a decompression chamber on board a supply ship (see Sealab II ), or the station is sealed under water and itself serves as a decompression chamber (see Aquarius) . The latter is only possible up to a depth of about 40 m.
• Closed station : The internal pressure in closed stations is identical to the air pressure at sea level , as in a submarine . To exit, divers have to use a lock that compresses them to the ambient pressure of the respective depth and then decompresses them again later. While the operating depth depends on the compressive strength of the station, exits can only be made at limited depths, since at greater depths even short exits would require considerable decompression times. The Russian station Bentos-300 (pronounced: Bentos minus three hundred ) was designed for depths of up to 300 m and had such a lock for exits.

The three-chamber system

While the habitat was also used as a decompression chamber in the Man-in-the-Sea I , Conshelf I, II and III experiments , the two functions were physically separated from each other in the Man-in-the-Sea II experiment. After the stay in the habitat, the divers got into a transport capsule in which they decompressed at the same time. Since the Sealab projects, the three-chamber system has been used, in which the divers change into a personnel transfer capsule (PTC ) after their stay in the habitat , which is sealed under water and thus lifted on board the supply ship. There it is coupled to a spacious deck decompression chamber (DDC for deck decompression chamber ), in which the sometimes considerable decompression phase is completed. The benefits are mobility, weather independence, and better medical surveillance.

The last stage of the development is the reduction of deep diving systems to deck decompression chambers and person transfer capsules as in the Draeger deep diving facility Bibby Topaz. The divers live for the entire mission under the pressure of the operating depth in a very spacious pressure chamber complex in the hull of the corresponding ship. For the individual diving missions, they are brought to the appropriate depth by capsule, where they get out and do the underwater work. At the end of the dive, they climb back into the capsule for transport to the water surface, which is coupled to the pressure chamber complex on the ship. At the end of the mission, which lasted several days, the decompression phase, which again lasts several days, begins. Systems of this type are used today for all offshore saturation dives.

Underwater stations have thus abolished themselves through their own development.

Components of underwater stations

• Habitat: The actual station
• LSB (life support buoy), which is necessary for the supply of energy, breathing air, fresh water, telecommunications and telemetry. The connection between habitat and LSB is made via a multi-core umbilical (from umbilical cord , English for umbilical cord), in which all tubes and cables are united.
• PTC ( personnel transfer capsule ): If decompression is not carried out in the habitat at the end of a mission (i.e. in all missions at a greater depth), the aquanauts climb into this capsule, which is still sealed at the operational depth. It is then raised on deck and coupled to the deck pressure chamber (see DDC) in which the decompression is performed.
• DDC (DDC for deck decompression chamber ): This chamber is located on the supply ship and is used for both controlled compression before the mission and decompression at the end of the mission. The advantage of a pressure chamber on board is mobility, independence from the weather and better medical monitoring.
• Supply ship (English support vesse l): While there were massive problems at the first stations due to the swell when sinking over the side of the board, it later became apparent that the ideal shape of the supply ship is that of the catamaran , with the habitat from the middle the ship can be lowered into the water. In order to achieve this shape, two ships were connected to each other by a platform in a 'U' shape at some stations.
• Land station: This station monitors all processes and houses a diving base, technical studios and accommodation.

Exits

The free space around the habitat that can be reached when exiting is described by an ellipsoid

Either common compressed air diving equipment or long hose connections to the habitat are used for exits . The hose variant is referred to in English as hookah , the Hindustani term for water pipe.

• Compressed air or rebreather diving devices : The advantage of compressed air diving devices is their mobility, which can also be a major problem for fully saturated divers if they can no longer find their way back to the habitat in poor visibility. There are then two possibilities either a life-threatening decompression sickness when trying to get to the surface of the water, or death by suffocation. For this reason, most programs have placed markings and ropes around the habitat to prevent divers from getting lost.
• Hookah hoses are correspondingly safer, but they also restrict freedom of movement and can get tangled.

Thus, the horizontal radii of the exits are limited to the amount of air supply or the length of the breathing tube. But the distances above and below the level of the habitat are also limited and depend on the depth of the operation and the associated saturation of the divers. The space available for exits thus describes the shape of an ellipsoid around the habitat.

In the Tektite I program , the habitat was at a depth of 13.1 m. Exits were limited vertically to a depth of 6.7 m (6.4 m above the habitat) or 25.9 m (12.8 m below the habitat level) and were horizontal to a distance of 549 m Habitat carried out.

advantages

Stationing divers on the seabed has various advantages over surface-based dives:

• Observations can be carried out at any time of the day to study the behavior of both diurnal and nocturnal organisms.
• Underwater stations in shallow water can also be used to record divers from greater depths in order to perform much of the decompression in them. This principle was used in the Conshelf II project .
• Saturation dives offer the ability to dive with short intervals, which is not possible from the surface.
• Risks related to diving and ship operations at night can be minimized. In Habitat La Chalupa 35% of all dives took place at night.
• To do the same amount of dives from the surface of the water instead of Habitat La Chalupa , eight hours of decompression time would have been required every day.

disadvantage

• Cumbersome handling
• high personnel and material costs
• limited mobility
• high costs

Relevant projects

	year	Status	Max. depth	description
	1962	set	61 m	Man in the Sea I , USA The first Aquanaut was Robert Stenuit in the Man-In-The-Sea I project by Edwin A. Link. On September 6, 1962, he spent 24 hours and 15 minutes at a depth of 61 m in a steel cylinder and made several exits.
	1962	set	10 m	Conshelf I or Precontinent I (Jacques-Yves Cousteau), France This first project in Jacques Cousteau's Conshelf or Precontinent series was carried out with the aid of the Diogenes habitat off the coast of Marseilles at a depth of 10 m. Albert Falco and Claude Wesley lived in it for a week. Diogenes was a steel cylinder 5 m long and 2.5 m in diameter and had a television, radio, library and a bed.
	1963	set	25 m	Conshelf II or Precontinent II (Jacques-Yves Cousteau), France / Sudan This facility in the Shaab Rumi reef off Port Sudan consisted of three underwater stations: the main house starfish in the shape of a starfish at a depth of 10 m a garage for the submarine Diving Saucer at a depth of 10 m the Deep Station depth laboratory at a depth of 25 m Five people lived in the main house for a month, and two more in Deep Station for a week .
	1964	set	126 m	Man in the Sea II , USA In June 1964, Robert Stenuit and Jon Lindbergh spent 49 hours at a depth of 126 meters in Edwin A. Link's Man-in-the-Sea II program. The habitat consisted of an elastic balloon called SPID ( submerged portable inflatable dwelling , English for submerged , portable, inflatable dwelling ).
	1964	set	59 m	Sealab I , USA Sealab I was a US Navy habitat. In July 1964 four divers spent nine days in it at a depth of 59 m. The facility was 12.19 m (40 feet) long and 2.74 m (9 feet) in diameter, giving a floor space of approximately 33 m².
	1965	set	62.5 m	Sealab II , La Jolla / California, USA Sealab II took place approximately 1 km from the Scripps Institution of Oceanography pier in La Jolla , California at a depth of 62.5 m (205 feet) between August 28 and October 14, 1965 to take advantage of seabed stations to explore. The habitat consisted of a steel cylinder 3.66 m (12 feet) in diameter and 17.37 m (57 feet) long, giving it an area of ​​approximately 63.57 m².
	1965	set	11 m	Glaucus , Plymouth , UK This self-made habitat consisted of a cylinder 3.7 m long and 2.1 m high and weighed 2 tons. Colin Irwin (19) and John Heith (22), both members of the Bournemouth and Poole Sub Aqua Club , lived there for a week at a depth of 11 m. The habitat had two beds and a phone. It took about six months to develop and cost £ 1000. CO 2 was filtered out of the air with soda lime and replaced with oxygen, so that no air supply from the water surface was necessary. The Human Interface Technologies team at the University of Birmingham added a digital reconstruction of the habitat to the virtual simulation of the Plymouth Sound , so that the system can at least be entered virtually again.
	1965	set	100 m	Conshelf III or Precontinent III (Jacques-Yves Cousteau), France This project was carried out near Nice at a depth of 100 m. Six crew members lived in this habitat for three weeks and tested potential work capacities during daily exits. The actual habitat was spherical and had two floors. It sat on a platform that acted both as ballast underwater and as a floating body on the surface of the water.
	1966-1986	set		Hydrolab , USA Hydrolab consisted of a cylinder with the dimensions 5.49 m × 2.44 m. It had an entrance lock so that decompression could be carried out at the end of a mission within the habitat and under the control of the aquanauts. It served as a research platform for around 500 aquanauts in 150 missions. In 1986 it was given to the Smithsonian Institution , where it is still today.
	1968/1972	set	13 m	Edalhab ( Engineering Design and Analysis Laboratory Habitat ), USA This habitat in the form of a lying cylinder was 2.6 m high, 3.3 m long and weighed 14 t. It was built by students from the Engineering Design and Analysis Laboratory . On April 26, 1968, four students spent 48 hours and 6 minutes in this habitat in Alton Bay, New Hampshire. Two more missions followed at 12.2 m Edalhab II, FLARE ( Florida Aquanaut Research Expedition ) This experiment by the University of New Hampshire and NOAA on the use of oxygen / nitrogen breathing gas also took place in Edalhab in 1972 . During these three missions, the habitat off Miami was positioned at a depth of 13.7 m. The conversion for this experiment increased the weight of the habitat to 23 t.
	1968-1974	set	30 m	Chernomor I and Chernomor II , Soviet Union This habitat consisted of a cylinder measuring 2.9 mx 7.9 m and a displacement of 62 t. The location was the Black Sea. The first series of missions ( Chernomor I ) began in July 1968: 28 aquanauts in 5 teams spent between 4 and 6 days at 12.5 m. After a reconstruction, the habitat (now Chernomor II ) was able to operate for 2 weeks independently of the water surface at 30 m. Between 1969 and 1972 aquanauts spent a total of 4,000 man-hours in the habitat in numerous missions. The longest mission lasted 52 days at 15 m with three to five people (1971). Due to the low negative buoyancy of 4 t, the habitat and the divers in it tilted once by 30–40 °. Another time it 'hopped' several times until it came to rest in the bank area.
	1968-1969	set	10 m	BAH I , Federal Republic of Germany BAH I (for Biological Institute Helgoland ) had a length of 6 m and a diameter of 2 m. It weighed around 20 t and was designed for a crew of two. The first mission in September 1968 with Jürgen Dorschel and Gerhard Lauckner at a depth of 10 m in the Baltic Sea lasted 11 days. A week-long shallow water mission in Lake Constance followed in June 1969. In an attempt to anchor the habitat at 47 m, she was flooded with the two divers in it and sank to the sea floor. It was decided to lift it with the two divers according to the required decompression speed. Nobody was harmed. BAH I gained valuable experience for the much larger Helgoland underwater laboratory . In 2003, BAH I was taken over as a technical monument by the Clausthal-Zellerfeld University of Technology and in the same year came to the Nautineum Stralsund on the island of Kleiner Dänholm.
	1968-1983	set	10 m	Malter I , German Democratic Republic This smaller habitat of 4.2 × 2 m was used at a maximum depth of 10 m in the Malter dam near Dresden. The 2-day mission in November 1968 took place at a depth of 8 m as the first habitat under a frozen water surface. In 1972 the habitat was overhauled and used until 1983.
	1969-1971	set	157 m	Aegir , Hawaii / USA This habitat consisted of two pressure chambers measuring 2.7 × 4.6 m, which were connected to one another by a spherical intermediate module. The entire system was laid out on a spacious platform and thus had very good towing properties. A total of 25 dives at 24.4 m, 3 dives at 60.1 m and in 1971 one dive at 157.3 m off Makapuu Point, Hawaii. Problems arose from the low temperature in the habitat and the limited communication in the helium atmosphere. Between 1971 and 1975 the facility was used for diving simulations.
	1969-1970	set	13.1 m	Tektite I , Tektite II and Minitat The Tektite habitat consisted of two towers, each with two floors. The towers were connected by a flexible tunnel. Tektite I took place at 13.1 m and lasted 60 days.
	1969	set	186 m	Sealab III, San Clemente / California, USA Upon completion of Sealab II , the habitat was modified to a depth of over 180 m (600 feet) and was named Sealab III . In February 1969, it was lowered near San Clemente , California. While attempting to repair a helium leak, one of the four divers suffered a fatal accident due to the lack of soda lime, which led to all other US Navy programs being discontinued.
	1969	k. A.	10 m	Sublimnos , Tobermory / Canada Joe MacInnis planned with the Canadian Habitat Sublimnos (based on limnology ) to offer a low-cost model that even diving clubs and smaller universities could afford. Although the habitat cost about $ 10,000 to build at the time, he wanted to reduce that price to about $ 2,000 in the future. He created the so-called Open Hatch principle , according to which everyone should have free access to the habitat. Sublimnos had two fold-out tables, an observation dome on the ceiling and four side windows. The habitable upper part was 2.7 m high and had a diameter of 2.4 m, ie a volume of about 10 m³. The habitat was supplied with air from the shore. In 1975 the MacInnis Foundation donated it to Seneca College in Ontario.
	1969	set		Helgoland , Federal Republic of Germany The Helgoland underwater laboratory is a former German underwater station and the first stationary diving system for saturation diving for use in colder waters.
	1969	set	12 m	Operation Atlantide , Lago di Cavazzo , Italy This system consisted of several interconnected cylinders and served as an underwater station at a depth of 12 m in the Lago di Cavazzo .
	1970	set	20 m	Shelf I , Bulgaria Shelf I consisted of a steel cylinder measuring 2.5 mx 6 m and was anchored off Burgas in the Black Sea at a depth of 20 m. In August 1970 the first three Aquanauts entered the facility and spent 4½ days there. The inside temperature was identical to the outside temperature (24 ° C) and the humidity was 90-95%. At the end of the mission, the divers were brought to the supply ship by capsule, where they were coupled to the pressure chamber located there. The decompression there lasted 33.5 hours. The second and last mission started in September, but was canceled after three days due to bad weather conditions.
	1972	destroyed	10 m	HUNUC , South Africa HUNUC (Abbreviation for Habitat of the University of Natal Underwater Club , in German: Habitat of the University of Natal Underwater Club ) was the first underwater laboratory in South Africa. However, shortly after its positioning, the facility was destroyed by conceptual errors and bad weather conditions.
	1972-1975 1986–	in operation	32 m 6.5 m	La Chalupa , from 1986 Jules' Undersea Lodge , Florida, USA The UWL La Chalupa was funded by the Marine Resources Development Foundation (MRDF) and the government of Puerto Rico. It consists of two cylinders that are connected by a rectangular room and thus offers a total area of ​​32 m². It is designed for five people and was used for eleven missions to depths of 32 m. Since 1986 the facility has been in use as the world's first underwater hotel at a depth of 6.5 m. MarineLab and Jules Undersea Lodge are now in the same lagoon.
	1973	set	30 m	Seatopia , Japan Marine Science and Technology Center (JAMSTEC), Japan This system was intended for missions up to 100 m and consisted of the following modules: the habitat (2.3 m × 10.5 m) the person transfer capsule (PTC) (1.7 m × 2.8 m) the supply ship that was built especially for this program and had a deck decompression chamber (DDC) to which the PTC could be coupled. Although completed in 1969, this habitat was only used for simulations for several years. In September 1973 Seatopia was anchored off Yokosuka, in southeastern Japan, at a depth of 30 m and four aquanauts boarded the facility. This mission lasted 68 hours.
	1973	Not translated	-	Village Sous-Marin ( Jacques Rougerie ), France Jacques Rougerie planned this underwater settlement on behalf of the US space agency NASA and the US oceanography authority NOAA as a station for long-term research stays of up to 250 scientists at a depth of 40 m off the Caribbean Virgin Islands .
	1974-1984 2008 – k. A.	set	9 m	Wildschütz UW-Station RI, RII, RIII, German Democratic Republic The first part of this small facility (RI) was built in 1974, the second (RII) between 1980 and 1984 and first used in the Bergwitzsee , where it was mainly used for training in diving military sports. It consists of a mushroom-shaped base with three capsules branching off from it. In 1998 it was transported to Wildschütz , where it was repaired in 2008 and reactivated at a depth of 9 m.
	1977	set	300 m	Bentos-300 , Soviet Union Bentos-300 (pronounced Bentos minus 300 ) was a maneuverable submarine that could be stationed on the seabed. It had an exit lock and was able to spend two weeks on the sea floor with around 25 people. Although announced in 1966, it was first used in 1977. The target depth was 300 m. After Bentos-300 sank in the Russian Black Sea port of Novorossiysk in 1992 , several attempts to salvage it failed. In November 2011 it was then dismantled and brought ashore over the next six months.
	1977	set		Galathee ( Jacques Rougerie ), France Jacques Rougerie's first underwater habitat was launched on August 4th, 1977. The outer shell of the semi-mobile and free-floating construction was made of steel, had window domes made of acrylic glass and had movable ballast bodies made of neoprene . With a volume of 56 m³ it offered space for four to seven crew members.
	1978	set		Aquabulle ( Jacques Rougerie ), France The diving bell Aquabulle was first used in March 1978 and was an underwater observatory for depths of up to 60 m. With a height of 280 cm and a diameter of 250 cm, it offered three divers space for several hours.
	1981	set	12 m	Hippocampe ( Jacques Rougerie ), France In December 1981 this habitat was put into operation at the point where Jacques Cousteau's Conshelf / Precontinent was positioned in 1962 . Hippocampe I was tested by Jacques Rougerie and Bernard Gardette, psychologist at Comex . Basically similar to Galathee , it consisted of an aluminum structure with large windows made of polymethyl methacrylate . The construction was able to accommodate two divers in a saturated state at a depth of 12 m for a period of 7 to 15 days. Hippocampe I is currently on display in Isla Mujeres , Cancun.
	1984	in operation	8 m	MEDUSA , from 1984 MarineLab , USA Although it was developed by the US Navy Academy as early as 1970 under the name MEDUSA (abbreviation for Midshipmen Engineered & Designed Undersea Systems Apparatus , English for Undersea Systems Device designed by cadets ), it was not completed until 1980. In 1984 it was donated to the Marine Resources Development Foundation (MRDF), renamed MarineLab and used for the first time. In 1985 it reached its final location in the lagoon at the Foundation's headquarters in Key Largo, Florida. MarineLab , also known as Classroom in the Sea, is the oldest habitat still in operation and consists of a steel water tank 5 m long and 2.5 m in diameter. It has a window with a diameter of 80 cm and a fully glazed observation dome made of acrylic glass with a diameter of 168 cm under the habitat.
	1989	in operation	19 m	Aquarius Reef Base , USA 'Aquarius' is an American underwater habitat and laboratory owned by Florida International University (FIU). It is located about fourteen kilometers southeast of Key Largo in the Atlantic at a depth of 19 m.
	1991	in operation	12 m	Eilat's Coral World Underwater Observatory , Eilat / Israel The first part of this observatory was created in 1975 and expanded in 1991. The facility can be reached from the bank via a footbridge and from the water surface via a corridor and is located at a depth of 12 m.
	1995	k. A.	6 m	Red Sea Star , Eilat / Israel The 'Red Sea Star' restaurant consists of three modules, an entrance area above the surface of the water, a restaurant with 62 panoramic windows 6 m below water and a ballast area below. The entire construction weighs about 6000 tons. The restaurant has a capacity of 105 people.
	1997	set	8 m	Scott Carpenter Space Analog Station , USA In 1997 and 1998 this small habitat near Key Largo, Florida was operated at a depth of 8 m for a period of 31 days. The aim was to increase student and public interest in science and NASA's space program.
	2001	k. A.	8 m	Divescope , New Caledonia Divescope was a larger diving bell made of Plexiglas and steel with a drying area in which one could fully emerge. She was in the lagoon off Nouméa , the capital of New Caledonia, at a depth of about 8 m (26 feet). Six people could stay in it for half an hour. Divescope was used, among other things, for underwater weddings. The construction is similar to Jacques Rougeries Aquabulle (see above).
	2004	in operation	5 m	Ithaa Undersea Restaurant , Maldives Ithaa ( dhivehi for mother of pearl ) is the world's only fully glazed underwater restaurant and is located in the Hotel Conrad Maldives Rangali Island . It can be reached via a corridor from the surface of the water, so that visitors can enter and leave the facility with dry feet and without the need for lengthy compression or decompression procedures. Ithaa was founded by MJ Murphy Ltd. built and has a weight of 175 t.
	2005 2007	set	12 m	Progetto Abissi , Italy This project, also known as La Casa in Fondo al Mare (Italian for The House Under the Sea ) by the diving club Explorer Team Pellicano , consisted of 3 cylindrical stations and served as a platform for a TV game show. It took place for the first time in September 2005 for 10 days. In 2007 6 aquanauts stayed in the facility for 14 days.
	2006	Not translated	k. A.	Hydropolis , Dubai Architect Joachim Hauser planned this major luxury resort project in Dubai . The concept envisaged 220 hotel suites and construction should have started in 2005. However, since the original location west of the Palm Jumeirah allegedly turned out to be unsuitable, the project was postponed until further notice. The facility was to consist of a land station where guests would be welcomed. They were then to be brought to the main area by train via a tunnel. The plan was to build a circular wall with a diameter of 210 m as the foundation of the system in the sea, then to pump out the sea water (785,000 m³) from its center and start construction on this basis. The project management should be taken over by the company SIBC Industrial Building Consultants , the technical advice by the company Siemens and the marine studies by the company Ostsee Kontor .
	2007	set	3 m	Biosub , Australia In 2007, the Australian Lloyd Godson lived in a container below the surface of the water for 12 days. The focus of this experiment was on self-sufficiency. There he produced his own energy with the help of an exercise bike and some of his oxygen with a system made from Chlorella algae, which should also filter the carbon dioxide from the air. Although the project did not go as smoothly as planned, it generated important insights for self-sufficient systems.
	2008	Not translated	12 m	Poseidon Undersea Resort , Republic of Fiji The underwater area of ​​the Poseidon Undersea Resort was to consist of a long corridor, on the long sides of which the rounded room modules (so-called pods , English for capsule) were to be linked and at the top two round communal areas such as bar and restaurant were to be linked. The facility should be accessible by elevator from the surface of the water and have 24 underwater suites with an area of ​​51 m² each, 70% of which should consist of 60 mm thick, transparent acrylic glass (polymethyl methacrylate ).
	2010	planned	30 m	Sea Orbiter ( Jacques Rougerie ) The Sea Orbiter is a planned French maritime research station. The initiator is the French "underwater architect" Jacques Rougerie. The total height of the Sea Orbiter should be approx. 51 m, of which 30 m are under water. The station should drift vertically and u. a. explore the Atlantic. The station was originally supposed to go into operation in 2010, but the project is currently still in the planning phase. A new possible time for a launch has not yet been mentioned, after only a single component, the " Eye of the SeaOrbiter ", was completed in May 2015 .

See also : Baylab

Secondary projects

Underwater hotel Utter Inn

Although the following projects have been mentioned several times in the press, concrete developments cannot be found or they do not represent a new development:

• Utter-Inn , underwater hotel by the artist Mikael Genberg in Lake Mälaren near Västerås near Stockholm / Sweden. It consists of a construction above water and a floating one below with a room. The popular project led to the creation of Genberg Underwater Hotels .
• Genberg Underwater Hotels is a more luxurious variant of the Utter-Inn and is located in the Manta Resort on the island of Pemba / Tanzania in the Indian Ocean.
• Atlantis Signature Suites are two suites in the Atlantis Hotel , The Palm in Dubai, which are located under the surface of the lagoon and have large panoramic windows.
• Planet Ocean Underwater Hotel : This design, planned for Florida, is based very much on the design of Poseidon Resort .
• Water Discus Underwater Hotel : This Polish concept, which won awards in 2011 but has not yet been implemented, consists of two large areas each in the form of a discus with an area of ​​around 1000 m², one below the surface of the water and the other above it. The underwater area should have 21 rooms and be 6 m deep.
• Chinese Deep Sea Mining Laboratory: In 2012, at the 5th China Beijing International Hi-Tech Expo , the China Ship Scientific Research Center presented the design of a deep sea laboratory planned for a depth of 1000 m and deployments of 33 people for two months is. The nuclear-powered facility is said to have the shape of a submarine and weigh 2600 tons with a length of 60.2 m, a width of 15.8 m and a height of 9.7 m. A smaller prototype for missions of 18 days with a crew of 12 should go into operation in 2015. Although no date has been published for the large version, experts assume a realization date of 2030. A presentation by the Chinese Ministry of Science in 2016 presented a similar station for a depth of 3000 m in the South China Sea and for missions of up to a month for several dozen participants. As a result, the project would be ranked number 2 on the list of the top 100 science and technology priorities of the Chinese government.
• Atlantica Expedition : The NASA environmental engineer, science fiction author and developer of the Scott Carpenter Space Analog Station Dennis Chamberland intended with this project to build the world's first permanent underwater colony and received support from James Cameron . However, the implementation of the project has not yet taken place.
• Aqua Star Hotel : This concept should consist of small modules and be anchored at a depth of 10 m. However, it has not yet been implemented.
• Calamar Park : Calamar Park is an open source project for the development of a new generation of underwater stations, but has not yet been implemented.
• The Pearl is a spherical habitat with a diameter of 2 m and several windows, which is anchored in the pool of the diving center Nemo 33 in Brussels at a depth of 5 m and has served as a restaurant since the beginning of 2017. It has several round windows and meals are delivered to guests by diver.

Fictional underwater houses and underwater cities

• Underwater smugglers base of the captain John Helena, called "the moray", in the shipwreck of the Discret below Cape Rosa in the volume The hiding place of the moray eel (Le repère de la murène) of the series Spirou and Fantasio by André Franquin . In many ways this band may have been directly influenced by the work of Cousteau.
• Underwater dome city Korralion in the volume Tiefenrausch of the series Spirou and Fantasio by André Franquin
• a secret city or settlement in the youth book The Silent Bomb: Black Death in Space from the Mark Brandis series or Space Partisans by Nikolai von Michalewsky
• "Atlantis", Stromberg's water or underwater base in the James Bond film The Spy Who Loved Me
• Basis in the comic The Manitoba does not answer and in the follow-up volume in Hergé's series The Adventures of Jo and Jette
• Rastapopoulos base in a city ​​submerged in the reservoir in the cartoon Tim and the Shark Lake
• City "Templemere", 7000 m deep, in the film Kapitän Nemo or Captain Nemo and the Underwater City from 1969, very freely based on a theme by Jules Verne
• City "Pacifica" in the film At 9 o'clock the earth goes under ( City beneath the Sea ) from 1971
• City "Equatoriana" in the Japanese film U 4000 - Panic under the ocean
• submerged cities in the comic Yoko Tsuno , "The City of the Abyss" or "Les Archanges de Vinea" by Roger Leloup
• Einsiedlerhaus in the film Around the World Under the Sea ( Around the World under the Sea )
• Underwater city of Atlantis and fish people living next door in the double volume The Devil's Triangle and The People of the Deep Sea from the comic series The Mini People by Seron
• various underwater cities in the TV series SeaQuest DSV
• "The City Beneath the Sea", located in the Aegean Sea , in the television series Voyage to the Bottom of the Sea and the like in other episodes
• the movable underwater drilling station "Deep Core" in the scifi film The Abyss . Most of the scenes in the film were shot underwater in real life. In addition to “Deep Core”, there is a rather imaginative alien underwater city in a deep sea trench, the eponymous “Abyss”.
• the underwater station "Deep Star Six" with nuclear energy supply in the horror scifi film of the same name.
• the underwater station "Shack 7" in the scifi horror film Leviathan . Like DeepStarSix or, before, Alien , the plot is about the counting verse "10 little negroes". The divers use armored suits .
• Submarine base in the two- or three-volume comic The Fight for the World in the Blake and Mortimer series . Dry access via cave system, helmet diver exit.
• fictitious underwater station as part of the Expo 1998 exhibition ( Lisbon ).
• various underwater cities and stations can also be found in the classic science fiction novel, for example in the books by Arthur C. Clarke , Edmond Hamilton ( Captain Future ) and also in Flash Gordon .
• Underwater dome city "Otah Gunga" in the movie Star Wars , Episode I, inhabited by amphibious "Gungans", including the idiot Jar Jar Binks.
• Underwater city “Rapture” as the setting in the BioShock computer game , LeMU in the Ever 17 game, OceanLab in the Deus Ex game, Lumeria in the Champions Online game.
• "Looking Glass" in the television series Lost , as well as stations in the series SeaLab 2021 .
• the underwater cities in the role play system LodlanD
• the fictional, once submerged and now inhabited Kanoli cave system in Clive Cussler's novel Im Todesnebel (Pacific Vortex)
• the station "Neptune" of the Martel Corporation in the horror film Lords of the Deep
• ORCA (Oceanic Research Center Australia) is a marine research station on the Great Barrier Reef in the Australian television series Ocean Girl .
• Counter-espionage underwater station at Cap Canaveral in Dan Cooper No. 11 Storm on the space base

Web links

Commons : Underwater station  - collection of pictures, videos and audio files

• Article u. a. about projects in the GDR

Individual evidence

1. ↑ ^{a b c d e f g h i j k l m n o} James W. Miller, Ian G. Koblick: Living & Working in the sea . New York 1984, Van Nostrand Reinhold Company, ISBN 0-442-26084-9 .
2. ↑ ^{a b c d e} Conshelf I, II & III. (No longer available online.) Archived from the original on June 9, 2014 ; accessed on September 2, 2016 . Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.  
3. ↑ G. Haux: diving technique . tape 2 . Springer-Verlag, December 11, 2013, p. 277 ( Tauchtechnik - Original title: Tauchtechnik . 1970.).
4. ↑ Sealab I Project Group: Project Sealab Summary Report: An Experimental Eleven-Day Undersea Saturation Dive at 193 Feet . Ed .: Office of Naval Research. Dep. of the Navy. ONR Report ACR-108. Washington, DC June 14, 1965.
5. ↑ Press box: Dräger Safety supplies deep diving system for Norwegian diving support ship “Bibby Topaz”. November 23, 2006, accessed December 29, 2016 . 
6. ↑ OV Ehm, Max Hahn, Uwe Hoffmann, Jürgen Wenzel: The new Ehm - diving even safer . 9th edition. Müller Rüschlikon Verlags AG, Cham / Switzerland 2003, ISBN 3-275-01484-6 , p. 343 .
7. ↑ Keneth D. Johns: SCIENTIFIC Diver Rebreather Fatality: An Incident Review . Ed .: University of North Carolina Wilmington. AAUS_2013_18. Wilmington, North Carolina, USA. ( online ).
8. ↑ Bruce B. Collette: Results of the Tektite program: Ecology of coral-reef fishes . Ed .: Natural History Museum, Los Angeles County. Los Angeles 1972 ( online (PDF) ).
9. ↑ USNUM Curator: The United States Naval Undersea Museum, Keyport: Sealab II End Bell. September 19, 2016, accessed November 29, 2016 . 
10. ↑ Sealab I Project Group: Project Sealab Summary Report: An Experimental Eleven-Day Undersea Saturation Dive at 193 Feet . Ed .: Office of Naval Research. Dep. of the Nav. ONR Report ACR-108. Washington, DC June 14, 1965.
11. ↑ DC Pauli & GF Clapper: Project Sealab Report: An Experimental 45-Day Undersea Saturation Dive at 205 Feet . Ed .: Office of Naval Research, Department of the Navy. ONR Report ACR-124. Washington, DC March 8, 1967.
12. ^ "Week Under Water" video on YouTube. British Pathé, accessed November 24, 2016 . 
13. ↑ Dave McMullan: BBC Radio 4: An act of extraordinary, underwater DIY. September 7, 2015, accessed November 24, 2016 . 
14. ^ Chip Clark: Smithsonian Institution Archives: Hydrolab Being Moved into National Museum of Natural History. April 1986, accessed November 29, 2016 . 
15. ^ US Department of Commerce, NOAA: NOAA's Office of Undersea Research Fiscal Years 1982 and 1983 Report . Rockville / Maryland, USA September 1984.
16. ↑ Christina Reed, William J. Cannon: Marine Science: Decade by Decade . Ed .: Facts On File, Inc. New York 2009, p. 165 ( limited preview in Google Book search).
17. ↑ University of New Hampshire: Guide to the Engineering Design and Analysis Laboratory Habitat (EDALHAB) Files, 1967–1978. Retrieved October 23, 2016 . 
18. ^ Periscope Film: Science Screen Report on YouTube. Retrieved October 23, 2016 . 
19. ^ Underwater station BAH I. Accessed on September 12, 2016 . 
20. ↑ NAUTINEUM lends out underwater station and shark diving vehicle. August 10, 2016. Retrieved September 12, 2016 . 
21. ↑ Bill Bunton and Mary Heglar: San Diego Magazine: Death of an Aquanaut , excerpt from Target: The Awa Maru . June 29, 2007, accessed December 21, 2016 . 
22. ↑ Douglas L. Hicks: 'Bargain Basement' Habitat . In: Popular Mechanics . tape 135 , no. April 4 , 1971 ( 'Bargain Basement' Habitat ).
23. ↑ Michael Behar: Popular Science: 1200 square feet under the sea. January 2007, accessed November 29, 2016 . 
24. ↑ Jules Undersea Lodge Homepage: The Lagoon at Key Largo Undersea Park. Retrieved September 4, 2016 . 
25. ↑ ^{a b} Marko Martin: MARE - Visions of Reality . No. 66 . MARE, Hamburg 2008, ISBN 3-936543-56-9 , pp. 86-93 .
26. ^ Michael Goldschmidt, Ilka Weber: Unterwasserwelt.de: Wildschütz UW station. (No longer available online.) April 2008, archived from the original on September 17, 2017 ; accessed on September 2, 2016 . Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.  
27. ↑ Wrecked Soviet research submarine recovered. (No longer available online.) April 11, 2012, archived from the original on January 8, 2017 ; accessed on September 12, 2016 . Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.  
28. ↑ ^{a b} SeaOrbiter website. Accessed August 30, 2016 . 
29. ↑ Hippocampe, an underwater habitat. Accessed August 30, 2016 . 
30. ↑ Marine Resources Development Fondation: MarineLab Undersea Laboratory. Retrieved November 28, 2016 . 
31. ^ The Underwater Observatory Marine Park Eilat: History. Retrieved December 28, 2016 . 
32. ↑ Homepage of the 'Red Sea Star'. Archived from the original on April 4, 2016 ; accessed on November 18, 2012 . 
33. ↑ Edie Cohen: Under The Sea . In: Interior Design Magazine . July 1999, p. 142 f .
34. ↑ Capital Community College: NASA Under the Sea: The Scott Carpenter Space Analog Station . Ed .: NASA - AMATYC - NSF Project Coalition. LTA 19.
35. ↑ Japanese couple rehearses underwater wedding off Noumea. (No longer available online.) 2001, archived from the original on November 15, 2016 ; accessed on August 30, 2016 (English). Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.  
36. ↑ Conrad Maldives Rangali Iceland website. Retrieved December 7, 2016 . 
37. ^ MJ Murphy Ltd. Homepage. Retrieved December 7, 2016 . 
38. ↑ Explorer Team Pellicano homepage. Retrieved December 7, 2016 (Italian). 
39. ^ Hydropolis - A dream or reality. Retrieved February 16, 2011 . 
40. ^ Brian Barrett: Hydropolis: A hotel on the bottom of the ocean. October 6, 2010, accessed August 30, 2016 . 
41. ↑ Blueshift Engineering: Hydropolis construction video. Accessed August 30, 2016 . 
42. ↑ Jamie Stewart: Hydropolis fights further troubles. December 20, 2008, accessed August 30, 2016 . 
43. ^ Lloyd Godson: Lloyd Godson: BioSUB. Retrieved October 26, 2016 (English). 
44. ↑ Poseidon Undersea Resorts homepage. Retrieved December 7, 2016 . 
45. ↑ Unusual hotels of the world: About Utter Inn. Retrieved October 22, 2016 . 
46. ↑ Genber Underwater hotels homepage. (No longer available online.) Archived from the original on February 29, 2016 ; accessed on October 26, 2016 (English). Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.  
47. ↑ BBC: Underwater hotel rooms: Is down becoming the new up? December 3, 2013, accessed October 26, 2016 . 
48. ^ Adam Nebbs: Underwater hotel a step closer to reality, but don't hold your breath. Post Magazine. January 15, 2016, accessed September 30, 2016 . 
49. ^ Deep Ocean Technology. Retrieved September 30, 2016 . 
50. ↑ Lukas Zimmer: ORF.at: Sleep with the fish. December 26, 2013, accessed October 26, 2016 . 
51. ↑ Stephen Chen: China Daily Mail: After orbiting space lab, China wants an undersea lab for deep sea mining. July 8, 2012, accessed October 26, 2016 . 
52. ↑ Alessandra Potenza: The Verge: China wants to build an underwater 'space station' 10,000 feet below the surface. June 10, 2016, accessed October 26, 2016 . 
53. ^ The Atlantica Expeditions: The First Undersea Colony. Retrieved December 28, 2016 . 
54. ↑ Aqua Star Underwater Hotel. Retrieved December 28, 2016 . 
55. ↑ CalamarPark.com homepage. Retrieved December 28, 2016 . 
56. ^ Waverly Colville: Reuters: Belgian entrepreneur invites you to scuba dive to dinner. January 31, 2017, accessed March 11, 2017 .