Flotation bags instead of liferaft?

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brownsox

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In PBO December 05 there was an account of how a guy set up his 21 footer for transatlantic. He took 8 self inflating flotation bags (250kg pos buoyancy each) instead of a raft - "my chances were highest if ... (I made) my boat into my liferaft".
Sounds like a good idea - what do people think? And if so why have I never heard of this before? We're only planning a channel crossing but it feels like the atlantic to me ... In a 24 footer there really isn't space for a liferaft where it would be easy to deploy.
And if people do think it's a good idea, anyone know where to source them?
 
I think its a great idea, there must be a boat builder around who does this as part of their design? /forums/images/graemlins/wink.gif
 
Not much use if your boat catches fire. If flotation bags were a good idea everybody would have them...but the're not......so nobody at all has them.
 
Better than nothing for sure, but do consider that in order for such flotation bags to actually ....float, they need the boat to be full of water and very low above the waves.

Life on-board would be miserable and even the possibility to patch the water-ingress might be nigh impossible, with the accomodation filled by inflated bags....

No use in case of a fire, also.

My vote would always go to a liferaft, or at least a ready-for-deployment tender.
 
My God, you must have your boat stuffed full of duty frees
if you can't find room for a liferaft on a 24 footer
Stick the raft on the roof, that should be the last part of
the boat to disappear, i wear mine on my back with the
RIPCORD tied to my wrist!!!
Fire and floatation bags don't mix!!
Cheers Tony
 
We carry a dinghy, but no liferaft.

Yes, fire does always pose a potetial threat but sinking is never an issue, with the carfully distributed foam around the boat it will still sail, fully flooded. What I mean by fully flooded is about 20 - 30 cm of water.

I suspect this is one of the reasons why Etap 32s has a higher STIX rating than a Contessa 32 (as published by YM).

It would be interesting to see if there are any stats available to determine how many boats have been lost through fire at sea compared to hitting submerged object/downflooding/holing etc.

I dont believe that a liferaft is the answer for complete safety though, lets consider the numbers lost in the 79 Fasnet and the Sydney - Hobart disaster, those who abandoned to liferafts to die, their floating boats later found.
 
I have mused about this but it can't be good enough to just stick some floatation bags around - they would have to be heavily anchored to hull. Otherwsie reliance on flotation bags would be like supporting the entire boat on the deck joint and ceilings - from underneath. I am not at all sure how many boats could survive being dangled like that.
 
There was a guy based in Brighton Marina years ago(1982?)who had them fitted to his boat and was hawking them around as a commercial venture,but I don't think it came to anything.Main problem as somebody said is fire,they also severely limit storage and access to same.
 
These may have been 'Unsink', seem to remember they were based in Cowes getting on for fifteen years ago.

I think that fitting a canting keel might be a better bet. Just drop it when you're sinking. About half of the canters built to date have tried this, although prematurely. I believe that one yachtbuilder has also tried something similar with fixed keels.
 
There is a system designed to be installed under bunk cushions.

Folded down with activation cylinders below, they take up little useable space, just a bit for the cylinders and attachments.

The main issues are:

Chaffe prevention (and therefore inspection / servicing) over the years of non-use.

Secure fastening down to structural hull members to support the weight of yacht, you can't rely upon the coachroof.

Chaffe defence when deployed. Assume the air bags are pressing against hull sides and moving violently, possibly against exposed screw heads or fittings, other loose items of stowage, floorboards etc. etc.

All of this is no use in the event of fire, and possibly no use in event of catastrophic explosion if the structure is seriously compromised.
 
[ QUOTE ]
I think that fitting a canting keel might be a better bet. Just drop it when you're sinking. About half of the canters built to date have tried this, although prematurely. I believe that one yachtbuilder has also tried something similar with fixed keels.


[/ QUOTE ]

V good LOL
 
Hi, we made our first channel crossing last year and I agree, it seemed like we were about to cross the Atlantic. Beware of those who say you can't manage without this safety item or that vital piece of £500 gear. All life is a risk, and lots of people have died by risking their lives in liferafts rather than staying with their boat. You could hire a liferaft or you could do what the vast majority of people do, rely on an inflatable tender for coastal and channel hopping. I say vast majority because you only have to take a look round a marina to see how few boats have a liferaft. Some have a liferaft in a valise in a locker somewhere, for all the good that would do in a fire. If having a liferaft gives you the confidence to make the trip then buy one, but we all know how hard it is for ships to see a yacht, what chance of being run down in a liferaft?!

IMHO (and based on very limited experience) the essentials are lifelines, lifejackets, a good VHF, an inflatable tender, proper fire extinguishers and a full set of distress flares. Anything else is just an optional extra.

Enjoy the trip!
 
... and you can't rely on the liferaft working. Ask Phillip Watson (Hanse 371 sank in Irsh sea about 12 months ago)
 
i have an avon redstart that comes with two compressed air bottles for rapid inflation in an emergency.
this is my liferaft and i also think it is a clever idea, but i have never seen this set up on any other dinghys.
 
Do a search for turtle-pac. I investigated this option because, to me, it sounded like a good idea. As per the other posts though, there are several downsides and I went with a liferaft in the end.

I'm actually regretting buying the liferaft - it's too heavy, too bulky, and just about the only realistic place to keep it is up on deck whereas I would rather keep all that weight as low as poss. IMO, there is definently a lot to be said for the argument of having a tender kept inflated (or part-inflated) on deck.
 
Get real Simon your advice is badly flawed I think if you sail
offshore without a liferaft it is irresponsible. Most offshore
cruiser i know and i would say 90% carry a liferaft or rubber
dinghy. Of course stay with the ship, UNTIL it vanishes under
you, thats the fatal mistake the yotties made in Fastnet!!
they got in the liferaft before their yachts sank.
God i hope you don't take family when you go cross channel
you can and the rest of you anti-liferafters argue all you like
Mine is not an opinion It is a Fact do not go boatingwithout one
Crikey i'm beating the drum this time!!!
Cheers tony
 
Incredible quantity and variety of replies already- thanks!
My take on it so far: Fire is not the main hazard, sinking (quickly) is, in our view. Liferafts are occasionally unreliable (see recent post on a test), and once launched, v uncomfortable ie sickness causing - and hard for rescuers to find. If these bags keep the boat afloat for some hours it will be easier to find, and you may even have limited access to your food water and radio - and shelter. One bag in the forepeak, one under the cockpit floor (we have an outboard), others as req in saloon ... ? I feel happier with that prospect than with taking to a tiny inflatable raft or boat. And we also do have a flubber - the bags would buy time to inflate it. But would the bags force the lid off the boat? Sounds unlikely but it's an interesting point - any techy experts know? Ours is a well built Trapper TS240.
 
[ QUOTE ]
....sinking is never an issue, with the carefully distributed foam around the boat it will still sail, fully flooded. What I mean by fully flooded is about 20 - 30 cm of water.

[/ QUOTE ]
Either I misunderstood what you mean, or there is a serious and potentially dangerous misconception here:

- when the boat is floating normally, the water level on the outside would be at least 30-40 cm above the cabin floorboards, right?

- to have the holed boat float without setting deeper in the water, you would need to fill with buoyant material all the bottom of the hull up to the waterline (that's Archimedes' law, not me!).

Not impossible per se, but that's clearly not the way ETAP's are built.
Unavoidably, to allow room for internal accomodation, they have spread the buoyancy around the hull, meaning that an "unsinkable" boat full of water will necessarily float much below its regular waterline.

Better than sinking, by all means! /forums/images/graemlins/smile.gif

...but I would very strongly doubt that the boat would be able to sail under these conditions.
 
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