BC Power Inflator, do we really need it ?

[Cave Diver]

3) Thanks for bringing this, I did not know those exist but I would probably pick one for my dry suit.

I'm not really sure how much variation there are between inflators and if they have a published flow rate, so I'm not sure how easily this information will be to find. I do know there is quite a bit of difference in the fill rates between some of my wings.

I'd be curious to know if anyone makes an inline flow restrictor for wing, similar to what is used when doing O2/nitrox analysis and if something like that would be beneficial to cold water divers?

 

[Cave Diver]

thanks Cave Diver, I think I understand all your reasoning completely and find myself on the same page

Wow, I think this is a first for me!

I should probably quit now while I'm ahead!

You're welcome, glad I could help some with your thoughts.

 

[elan]

They make some shut down gadgets but people say they are not easy to operate in thick gloves. Some mention the same technique as you have pointed out, shutting down the post, swim down and use dump valve to dump the air. For sure I have to practice doing this soon, lucky me I have some time till the really cold season starts

It's always nice to brush up the thoughts listening to opinions of more experienced people, though I might not recognize all reasoning behind all advices through the prism of my very little experience But I'm trying

 

[rstofer]

Rescue is going to be problematic whether you are the rescuer or the victim. It will be life-threatening if you are the victim and your rescuer can't get you positive at the surface.

You are also thinking about warmer water. I have to make up for over 20# of buoyancy change just in my wetsuit. That doesn't count the 8# of change from my HP100.

I don't think I'll give up my power inflator any time soon.

Richard

 

[spectrum]

How would cold water affect this situation in your opinion ?

On my first ice dives my infalator valve frozen a partially open state. I traced it to a loose inlet fitting that was allowing water to be aspirated into the valve. It essentially was a snow machine in there. The fitting had never been touched in 3+ years. Maybe it was the cold and coefficient of expansion, I'll never really know. The valve had been serviced a few times but the fitting was never disturbed. We turned the dive but took our time getting out with an occasional burp of my back dump. The next day I dove that same BC under the ice with no problems.

Even after that I say leave the power infaltor in place. The slight chance of a problem is outweighed by the convenience an reduction in task loading. Additionally it keeps you in a common configuration. If a buddy needs to get you positive there will be no unneeded challenges.

If it does go berserk you should be trained in disconnecting it. Then oral inflation (which you also practice) is the fall back.

Pete

 

[rab1412000]

If you need to change depth quickly, I suspect that fin kicks will be a lot more effective than trying to use your BCD for propulsion. And it will be a lot easier and quicker stopping when you get to the depth you want to be at by stopping kicking than by adjusting the gas in your BC.

i have been in downcurrents where finning alone wont be enough. a good inflate of the bcd (with your hand on the purge to avoid accidental shoot up) is necessary to help you fight it.

just my 2 cents

 

[JohnQPS122]

I agree with rstofer, the power inflator can be a life saver (yours or someone else's)during an emergency (or to prevent one) at the surface. You hope you ever need it, but there it is when you do. Like an air bag in a car, I suppose.

 

[Slonda828]

This question came to me after working harder on my buoyancy skills and starting diving the no BC configuration. At this point I have managed to deal with buoyancy changes that breathing out 50 cuf of air make, which is approx 4lb. The question came to my mind right after is if I'm weighted properly and do not have to put and dump all those huge amounts of air into the BC would not it be more safe not to have the hose connected at all and just inflate the thing orally, one will not need to do this many times anyways. This will eliminate the risk of the runaway inflator altogether. I know some people dive this configuration.

It would be nice to hear come comments from our more experienced members. I do not see any great risk here but can see a huge mitigation strategy especially when diving extremely cold water < 38-40F.

Thanks a lot.

Elan, it all depends on what you want to do. Sometimes I dive no BC, sometimes I dive with an old horsecollar BC that only has oral inflation, and sometimes I wear a tech rig. I think it's all about the mission. If the mission calls for more buoyancy that your lungs can compensate for, then you wear a BC. When I dive a drysuit in Dutch Springs with a steel 120, I wear a tech rig. Nobody I've ever met has can lung 8 lbs worth of negative buoyancy. When I am just diving shorts in the Bahamas or Florida with an AL80 or steel 72, then I do not even wear a BC. If the boat makes me wear one, I throw the horsecollar on because I do not have any low pressure ports on any of my doublehose regulators and it's easy to put on over top of my military harness.

I also do some dives where I leave my LPI disconnected, or disconnect it half way through to practice task loading and managing buoyancy without a power inflator. I agree with everyone else mostly though, I've only ever had one power inflator failure, and it was totally managable just by venting the extra gas via the butt dump. So I would say that you would not be any safer by taking it off.

I applaud your continued skills development and willingness to try new things and challenge yourself.

 

[H2Andy]

as has been stated, no, you don't need it

but it sure is convenient

your other option (assuming you're still using a BC) is to orally inflate it, which is much more cumbersome and slow, and it ties up all your attention

bc inflator failures are extremely rare, and the solution (to disconnect it asap) is eminently doable

 

[jtivat]

If you have to ask the question then you are not comfortable enough with your diving to not use it.