Having some experience on rafts in play, it seems like if you turn a raft upside down you get some benefits because you are suspended above the water. You don’t have to worry about the floor leaking, nor sharks or other large fish bumping into you directly, also you have better heat retention as you are not on a fabric directly in the water, but suspended over air. You could even put drainage holes in it to let what water gets on the floor drain out.
Yes I can see that it does make it top heavy, and may be a issue in rough seas, but perhaps a mid level floor would work well, still above the water, but with more stability.
Is there any reason life rafts are not designed like this, besides that’s the way we always have done this before?
There are life rafts that have a top to them which offers some protection from the elements. One of those was on an episode of the Deadliest Catch when a boat sank and the Coast Guard rescued some survivors.
I think the main issue is stability. If you are on an upside-down raft, your CG is higher, making the raft easier to upset. Using it upright, your CG is lower – perhaps below the waterline. Also, an inverted raft makes a nice pocket to catch wind. In even moderately choppy seas the raft may turn over if there’s a wind blowing. And of course, it would be easier to roll off the raft if you’re sitting on its bottom.
Life rafts for open waters are sophisticated beasts. Having grown up in a country where ferry rides were routine, I memorized the instructions for the ubiquitous Viking brand often enough. (Ferry rides can be very boring when you’re 12.)
This link gives a nice cut-away view of an inflated life raft, - a bit on the large side, but the concept is the same whether it’s a 4-person yachting raft or the cruise ship 150-person model.
The stability issue is mostly handled by underwater pockets unfolding and filling with water - making it harder to overturn the raft. There’s a double-ring and double-floor design - people would be at high risk of exposure if there was only a layer of rubberized fabric between them and the ocean. One real problem was the damn thing inflating upside down, something that has apparently only been solved properly in recent years.
From what I understand from buddies in the merchant marine, all of whom have spent 24 hours adrift in a raft, comfort is sorely lacking. And if the seas are a little on the rough side, seasickness becomes a real issue.
Hey, Mr. LA - we seem to be sharing the same threads a lot lately!
I’m thinking that a possible reason maybe that when the raft is inverted there would be no support for the floor, and if the load was heavy it may rip or separate from the inflated rings.
To engineer one that could support the weight may detract from its “stow ability.” Of course I am refering only to the rafts that are used on smaller craft
NadaHappyCamper
All airline life rafts I’m familiar with are the double-ring-floor-in-the-middle design as linked to by Johnny L.A.. As are the military transport liferafts shown in his first link.
Small 1 and 2 person rafts that I’m familiar with do have a single tube design with the floor on the bottom. The reason is stability. And generally in a raft that small even if you flip it over to put the floor on the top it doesn’t float high enough to get your butt out of contact with the water surface.
So you’re not gaining much in the heat transfer department while losing a bunch in the stability department. Getting & staying dry is uber important, Job One really. Anything that invites flipping & getting wet again is strongly avoided.
