The topic of inflating a drysuit when you go Out of Air (OOA) has come up in several threads as a result of a recent accident. The gist of those threads is that if a drysuit is used as alternate or critical buoyancy, you must have a plan in the event of a failure. I'm going to post a few thoughts here to keep from muddying other threads with off topic conversation, or hiding it in a thread that drysuit diver may not ever read.
With that being said, I'm going to present 3 ideas for orally (manually?) inflating a drysuit for your consideration. For those of you not familiar with drysuit inflation, it uses the same type of quick connect fitting that's found on your BCD low pressure inflation hose.
1. Add a low pressure inflation hose to a pony/deco/stage/bailout/etc. bottle. This is pretty common in Closed Circuit Rebreather (CCR) diving, because we don't actually breathe off the tanks, rather the tanks are plugged into the circuit and gas is fed into it via the low pressure hose. For those open circuit (OC) divers who carry a pony bottle, they could consider adding an inflation hose to the bottle and securing it out of the way so it's there when needed. The same idea can be used by tech divers who carry multiple stage or deco bottles. Be sure that the quick connect is cleaned and checked on a regular basis to make sure it's functional if/when you need it.
2. Unlike a BCD, drysuits don't have the option for orally inflating. One way around this is to break a wrist seal (or in an extreme case a neck seal) and purge your reg into the suit. Obviously this won't work if you're in an OOA situation, but if you're using a buddy's Octo, or have a pony bottle, it gives you an option for getting some inflation into the suit if needed.
3. The third option is similar to #2. The difference would be that you purge from your oral wing inflation into the suit. There would be some very limited reasons for using this option, because you're not going to increase your buoyancy since you're just shifting air from one chamber to the next. In fact, you may lose a little buoyancy if some of the gas escapes in the process. The main reason for doing this would be to alleviate suit squeeze that may allow you to move around a bit better.
4. Use a lift bag as an alternative buoyancy device. This one is my personal favorite, and I carry a minimum of one lift bag on every ocean dive. Often I carry 2, depending on the dive (one for signalling, one for alternate buoyancy when diving wet). On "big dives" I carry 3-4 as standard practice.
Obviously these are not things that I advocate as standard practices. However, they are "out of the box" options for a potentially dangerous situation (OOA/ Unable to inflate suit).
Also, in any of the scenarios described above, the dive should be over at this point. Any gas in the suit will expand on ascent and provide extra buoyancy.
Feel free to comment on any of the points listed, or add your own.
With that being said, I'm going to present 3 ideas for orally (manually?) inflating a drysuit for your consideration. For those of you not familiar with drysuit inflation, it uses the same type of quick connect fitting that's found on your BCD low pressure inflation hose.
1. Add a low pressure inflation hose to a pony/deco/stage/bailout/etc. bottle. This is pretty common in Closed Circuit Rebreather (CCR) diving, because we don't actually breathe off the tanks, rather the tanks are plugged into the circuit and gas is fed into it via the low pressure hose. For those open circuit (OC) divers who carry a pony bottle, they could consider adding an inflation hose to the bottle and securing it out of the way so it's there when needed. The same idea can be used by tech divers who carry multiple stage or deco bottles. Be sure that the quick connect is cleaned and checked on a regular basis to make sure it's functional if/when you need it.
2. Unlike a BCD, drysuits don't have the option for orally inflating. One way around this is to break a wrist seal (or in an extreme case a neck seal) and purge your reg into the suit. Obviously this won't work if you're in an OOA situation, but if you're using a buddy's Octo, or have a pony bottle, it gives you an option for getting some inflation into the suit if needed.
3. The third option is similar to #2. The difference would be that you purge from your oral wing inflation into the suit. There would be some very limited reasons for using this option, because you're not going to increase your buoyancy since you're just shifting air from one chamber to the next. In fact, you may lose a little buoyancy if some of the gas escapes in the process. The main reason for doing this would be to alleviate suit squeeze that may allow you to move around a bit better.
4. Use a lift bag as an alternative buoyancy device. This one is my personal favorite, and I carry a minimum of one lift bag on every ocean dive. Often I carry 2, depending on the dive (one for signalling, one for alternate buoyancy when diving wet). On "big dives" I carry 3-4 as standard practice.
Obviously these are not things that I advocate as standard practices. However, they are "out of the box" options for a potentially dangerous situation (OOA/ Unable to inflate suit).
Also, in any of the scenarios described above, the dive should be over at this point. Any gas in the suit will expand on ascent and provide extra buoyancy.
Feel free to comment on any of the points listed, or add your own.
