I though about that and asked in an above post. I slept on it and think that it would happen if you had the excess hose tucked in your cumber belt or the excess hose would just cycle through and you'd be alright.
Anyone willing to clarify?
When the hose is stowed in the 'Hog' fashion (around the neck) it is deployable by simply ducking the chin. It slides off easily. That is stage 1. It gives approx the same length of hose as a regular AAS set-up.
Once the OOA diver has secured the regulator, begun breathing and calmed, the donor is then able to disengage the remainder of the hose to deploy it at full length.
I make a point of practicing air donation 'in anger'. i.e. in the worst case scenario, where the reciever is panicked and/or air-starved... and may be brutal in securing the reg. Never had problems under those circumstances.
I liked the single file air share and surfacing under boat traffic examples....The rest are subject to opinion. I'm always thinking the worst case scenario when it comes to OOA.
I based my examples on personal experience coupled with reported real life incidents.
Personal Experience: teaching OW and Rescue divers AAS drills and noting their relative capacity to ascend under control whilst sharing air.
Reported Incidents: a number of diver deaths reported in the BSAC annual accident reports that reflect this scenario.
If you lose grip of an OOA diver and start rocketing to the surface while OOA sinks, long hose or not you're still separated and I don't think long hose is going to help keep that reg in anymore than a short hose. You may just get a few extra seconds to react.
The point of the long hose is that the divers can ascend as individuals, within a 'generous' proximity to each other and without direct contact ('death grip'). Under those circumstances, the divers suffer less stress and are able to better manage their buoyancy on ascent.
When sharing air from a conventional AAS, with a 'death grip', the divers have to closely coordinate their buoyancy. It is easy for one diver to become negative, whilst the other compensates with excessive buoyancy. That works only up until they happen to become separated (losing the 'death grip').
The PADI style 'Roman Handshake' is particularly poor for this. It relies on both divers sacrificing the use of one hand for the entire duration of the ascent... and having to manage their buoyancy with the other hand. If any other problem occurs (
i.e. flooded mask - likely when in such close proximity) then they either have to abandon their buoyancy control, or their 'death grip' or both... to deal with that problem.
Makes sense?
This question really started up because the only reason I heard of equipping a long hose was so that you could keep some distance from an OOA diver.
Given a calm OOA diver it may be beneficial to have one under certain circumstances.
Any air-sharing procedure should start with the donor ensuring that the recipient is calm before ascending. It's an important step that doesn't recieve the attention that it should in training scenarios.
If the recipient cannot be calmed, then it becomes more than an AAS ascent... and moves firmly into the realms of a full-blown rescue scenario. I also teach this in rescue class... where either active or passive panic by an OOA diver means that the donor has to take complete responsibility for the ascent. It can be simular to raising an unconsious diver...and requires a simular process.
