Octopus (diving)
In diving, an octopus is a second regulator to ensure an alternative air supply. It is used to supply a diving partner with air in an emergency. The name octopus is derived from the sea creature of the same name, the octopus , due to its multi-armed appearance, consisting of a second pressure hose and a second regulator . It is characteristic of an octopus that it goes from a common first stage together with the main regulator.
construction
A complete regulator system always consists of the pressure reducer, the first stage, and the actual regulator, the second stage. The octopus is also a second stage and does not differ from a regular regulator in terms of its design and function. Only the eye-catching coloring identifies it as a replacement piece of equipment. Technically, the octopus can be attached to a first stage together with the main regulator. However, this has the consequence that the octopus is not available if the first stage fails or the main regulator leaks out of control. This risk is particularly present in Central European waters due to icing . The octopus is therefore not a second, independent regulator system, as it should be used, for example, when diving in cold water or when diving in ice . In order to have in an emergency a redundant system, the octopus as an independent regulator can with an additional first stage at a second bottle valve to be mounted. For this reason, when choosing an octopus, it is advisable to use a regulator that is of a similar quality to the main regulator.
application
It is recommended to mount the octopus on the equipment so that it can be seen in the imaginary triangle between the mouth and the lower costal arch. This enables the diving partner to access it quickly and without a long search in an emergency, for example if the diving partner signals: “I have no air, give me air!”. It is therefore recommended that the octopus be clearly marked with a signal color - usually yellow. The main benefit of an octopus is to supply a diving partner whose air supply has failed with breathing gas in parallel to its own air supply. The helping diver continues to breathe from his main regulator , so that the difficult-to-handle alternate breathing from a shared regulator can be dispensed with. For safety reasons, it is therefore advisable to always ensure that there is a sufficiently large reserve of breathing air in order to enable both partners to climb to the surface using only one air supply , even while observing any decompression times.
Dangers in cold water
Since there is a risk of the first stage of the regulator icing up at water temperatures of approx. 10 ° C, two separate first stages should be used in these cases. Since such low water temperatures are to be expected in Central Europe even in summer, octopus systems in which the octopus is attached to the first stage together with the main controller should only be used in tropical and Mediterranean waters.
Conversely, the lower purchase price and the lower weight of the equipment speak in favor of using a common first stage. Bottle valves with only one outlet can only accommodate a first stage. Two sets, each consisting of the first and second stage, can only be attached to it with an adapter. For dives with high demands (deep dives, cold water, ice diving , wreck diving , cave diving ) at least two completely independent air supply systems should always be used.
Alternatives
Some associations, such as B. VDST or GUE recommend a long hose instead of an octopus configuration . With such a configuration, the hose of the main regulator is longer than that of the reserve regulator. In the case of a gas donation, the main regulator is given to the diving partner and the helper switches to his second regulator.
Individual evidence
- ↑ Thomas Kromp, Oliver Mielke: Diving: Handbook modern diving . 2., completely revised. and updated edition. Kosmos, Stuttgart 2011, ISBN 978-3-440-13121-3 , pp. 23 .
- ↑ VDST: Red Sea Deep South. (PDF) In: sporttaucher 5/2010 Retrieved on June 16, 2019.