Inflatable bags/tubes (for + flotation)

[CapnK]

Between the time of the discussion on Katies thread, and the story about Kensolo, I met some semi-transients, a 4X-Atlantic-crossing Frenchman who's hailed from Quebec for the past 10 years, and his girlfriend who is a bit newer to sailing than he is.

Their boat is a 52'-ish sloop, French-made, aluminum, which has twin rudders and a draft of 13 or so feet when the board is lowered (3' or so with it up). It's a pretty darn big boat, but he has made it so that it has positive flotation. He had the hull and deck made, and finished the interior out either himself or through contractors. Neat, and a nice job.

So I was thinking this rainy, bouncy evening, thinking about flotation, and those thoughts led to remembering some discussion about flotation bags which recently came up in the Katie Marie thread. I was sitting here, pondering what it would be like to have 3 or 4 large bags blown up inside the boat to keep it from sinking, and trying to envisage what it would be like to live and work with them in the way, even if only for a short while. Then,

I had an Idea.

What about if instead of having just 2-4 largish bags, you had many smaller ones? You could shift them around, to be able to get to parts of the boats interior as needed. That lead to me thinking of smaller, alternative blow-up-things that could be used.

What about truck and/or car tire innertubes? Remember those??? 

It makes me laugh to think of it, but they *could* work. One could even come up with ways to deal with the drawbacks, maybe. The biggest of course would be how to inflate many small objects quickly, if (or when) needed.

But would they work as well as a smaller number of large bags, in the end? Would the require more, less, or simply an equivalent amount of stowage space? Would they wear out quicker, or could you lessen chafe as you do with an anchor rode, by shifting them around on a schedule to lessen spot wear and chafe? Could a small boat sailor on a serious budget use them as an alternative to the high-dollar commercial solutions?

Doesn't the mind work in weird ways? Well, mine does, at least.

[Captain Smollett]

One plus: modularization.  If one leaks, the whole shooting match is not blown.  (Think MS vs OSS...hehe).

[Frank]

Capt K...you could use go cart tubes for those hard to get at spots,wheel barrow tubes next size up...the sizes are endless.  Bonus....ya could sell them off once you reach that south sea island...your own lil 'tube store'....I can see it now..a flag flying with " TUBES ARE US" on it....yep ..I'm liking it 

[Dougcan]

Man I tried real hard to resist, I really did! 

How about this one, only $17 for 200 of them at http://stores.ebay.com/Windy-City-Worldwide



(duck and run, laughing like a maniac!

[Godot]

I'm not sure if you are being really serious or not; but sure, a bunch of inflated anything will provide about as much flotation as another inflated anything that displaces the same amount of water.  But I see three big problems that, while technically solvable, would probably make this solution to much trouble to be practical.

The first, as you mentioned, is figuring out how to inflate a few dozen innertubes quickly.  After all, if it's gotten to the point where you need flotation, you likely need it right NOW.  Time spent individually inflating inner tubes would probably be time better spent trying to stop the leak; unless the hole is so big you are going down soon, at which point you probably don't have enough time to inflate the tubes.

The second is that they are not particularly efficient for their size.  What I mean is that a donut shape is not the easiest to fit into an irregularly shaped boat.  Plus, the have this big hole in the middle that wouldn't add to flotation at all.

The third is that you really need to secure this extra flotation to something or it might not be working in the right place.  For one thing, I don't think most hull to deck joints are designed to hold the weight of the entire boat.  For another, if the boat where, for instance, to go down by the head, all the tubes would slide to the aft until they hit something.  Small ones might go zipping out the companionway.  Big ones would likely block the companionway.  In the end, you might have a boat that was floating, but it might be floating vertically, ass up in the air.

[Captain Smollett]

The first, as you mentioned, is figuring out how to inflate a few dozen innertubes quickly.  After all, if it's gotten to the point where you need flotation, you likely need it right NOW.  Time spent individually inflating inner tubes would probably be time better spent trying to stop the leak; unless the hole is so big you are going down soon, at which point you probably don't have enough time to inflate the tubes.

That's an arguement against inflatable floatation that is normally uninflated, whether a single big balloon or many small ones.  You have to pump roughly the same amount of air.  The only difference in pumping time would be changing the nozzle and stowing the inidividual pumped ones.  There's a time difference, sure, but probabliy a small fraction of the total air-pumping time.

[Frank]

I REALLY like Dougcan's idea...17$ for 200...WOW...small,easy to store in tight places,something to 'play with' while in the doldrums and could offer extra $$ while offering a 'day care' service at anchorages !!! It's a WIN WIN WIN situation

[pogo2]

Nice idea Capt. have you ever watched a TV show called myth busters. They tried something  close to your plan but theirs was to raise a boat that had sunk. they used a 22' looked like a catalina anyhow they had to pump by air hose close to 2000+- ping-pong balls to raise the boat. I t worked but only for a short time. I do have a float bag for under the deck of my wooden snipe, just in case we do go over.

[Ol' Coot]

That's an arguement against inflatable floatation that is normally uninflated, whether a single big balloon or many small ones.  You have to pump roughly the same amount of air.  The only difference in pumping time would be changing the nozzle and stowing the inidividual pumped ones.  There's a time difference, sure, but probabliy a small fraction of the total air-pumping time.

How about several large float bags, commercially made or otherwise, in the V-birth, under the cockpit, etc  (outside your "survival area" and unlikely to migrate out of the boat).  Each could have a dedicated compressed air or CO2 tank attached to it.  If (or when as Capt K says) the poop hits the fan it would simply be a matter of opening a valve for each flotation device.  I think you'd want to do this as soon as you had any hint of need.  Once the bags were submerged it would be MUCH more difficult to deploy them.

Developing this idea shouldn't be too difficult...  Not too different than a self inflating liferaft, except that its inside your vessel.

[CharlieJ]

There once was a company who tried to market the exact idea you propose. If I recall correctly, they were called "Yacht Saver"

They went bust.

[Fortis]

they were a local Australian company. they went broke because of issues other then the product itself.