Emergency Bouyancy

[Ronnie_P]

Has anyone ever thought of (or heard of) installing something like an airbag out of a car on the corners of a boat? In the event of a submersion, or if the bow were to tilt too far down activating a pendulum, the bags could inflate on the deck and spare the boat a watery grave.. Actual airbags would not work because they are vented. But a water activated life raft does pretty much the same thing. Could save someone's life and or their motor and electronics. Also might drop insurance significantly.

 

[erikgreen]

Re: Emergency Bouyancy

I've thought about extra buoyancy a bit, mostly because I was thinking of installing a crane (A-frame) for lifting junk off the bottom as an exercise.

Short answer: It can be done, but for emergency use a life raft is probably both cheaper and provides better people protection. This could save your boat, but I'd think it would only decrease the insurance payout some, and have a limited return on investment.

You'd have to mount the float tubes near the waterline to avoid having water inside the boat, and that means some sort of hatch mechanism to seal, maintain, etc. If you mount the floats near the gunwale tops, then you'll get water in the boat in any waves, which will cause most of the damage a sinking would anyway.

Then there's the trigger mechanism, air tanks or pyrotechnics, maintenance of those and all the space they take.

There would probably be a narrow range of boats that could use this, as smaller boats would have no room for the system and larger ones would be too big for it to work on - weight increases as a function of hull volume, not boat length, so the floats, tanks, etc have to get larger as the hull does, and they'd be really, really large for anything above 30 feet long. Just look at the size of salvage lift bags for lifting that many thousands of pounds.

Of course, there is a style of boat with pre-inflated lift bags on the gunwales that is very hard to sink.. RIBs

Erik