will I sink or float 50N bouyancy aid

[dylanwinter]

the life jacket thread has been most edifying

and the last post was about 50N versus 150N

can anyone cast any light on the bouyancy offered by a 50N foam vest

what does it mean - what does 150N mean in realisty with a proper life jacet

because as Fisherman two pointed out most of that boyancy is well above the surface

I weigh 14 stone - sometimes plus a smidge

My normal gear tends to be overtrousers, a fleece or two and a screwfix coat

sometimes sailing boots

sometimes deck shoes

sometimes warm cotton traders style walking boots

I could kick the boots or the deck shoes off

the cheap walking boots float


so.... would I stay afloat


I have been in the water in the past wearing my small dinghy vest

sailing boots, jeans, overtrousers three layers and a spray top and did not feel as though I was going to sink - although the spray top was holding a fair amount of air as well

so..... can anyone cast any light on this matter

would I sink?

Dylan

 

[Lakesailor]

Just filling your boots and overtrousers with water won't make you sink.
It's water. It has the same density as .......erm, the water.
What you may lose is a bit of buoyancy that trapped air provided.

A lower rated vest will presumably allow you to float a bit lower in the water. But you aren't going to sink.

 

[Pye_End]

It seems to me that it is really a question of density rather than weight. For example a waterlogged fleece is pretty much the same density of water. A life jacket is there to keep your airways out of the water (orientation and wieght). In terms of buoyancy it needs to have about the same volume of air as your head, preferably designed to that it puts you on your back. Your overall weight is presumably pretty insignifcant. as you are not far off neutral buoyancy.

 

[dylanwinter]

on my back

It seems to me that it is really a question of density rather than weight. For example a waterlogged fleece is pretty much the same density of water. A life jacket is there to keep your airways out of the water (orientation and wieght). In terms of buoyancy it needs to have about the same volume of air as your head, preferably designed to that it puts you on your back. Your overall weight is presumably pretty insignifcant. as you are not far off neutral buoyancy.

I do not really want to be flipped on my back

I want to be anble to make some effort to get back aboard as opposed to just wait for rescue to come

recuers are few and far between on the humber in the winter

of course the only test is to go in the water wearing my normal sailing gear

getting a bit late in the season for such behaviour

Dylan

 

[maxi77]

A bouyancy aid did me fine when I capsized my laser, which I did many times. Yes it will keep you afloat, and if you are dressed appropriately allow you to swim.

 

[Billows]

I think Archimedes figured this one out a while ago

 

[dylanwinter]

a lot of doubt

in the other thread on scuttlebutt (huh what do they know compared to the clever people here) there were those who suggested that 50N was not enough

I would be amazed if they were selling PDFs for big blokes that would allow me to sink

but these things need to be asked and I have definately fallen out of love with my auto-inflate

at least until the manufacturers are prepared to publish the data on the web

Dylan

 

[LittleSister]

Dylan, You will float even without a buoyancy aid! (Just try swimming to the bottom of the river/pool and trying to stay there.)

As has already been said, the issue is keeping your mouth and nose out of the water. If you are incapacitated, you need a lot of buoyancy, and to be flipped onto your back. Unfortunately, the bulk and position of the buoyancy needed to achieve this will make it very diffcult to swim, or to climb a ladder, etc..

I would prefer a small foam buoyancy aid inshore. At sea I use a manually triggered gas lifejacket. If I found myself in the sea, I wouldn't plan to inflate it unless I had exhausted the possibilities of swimming and self-recovery or helping someone get me back in the boat. The downside of this strategy is that if I am knocked overboard unconscious it won't help me until (and if!) I come round.

I do have an old lifejacket, which is a hybrid - it has enough foam in it to serve as a buoyancy aid (albeit a bulky one), and it has a mouth inflated bladder which takes it up to lifejacket standard.

 

[William_H]

Buoyancy

In answer to your primary question Dylan yes I think that the 50n buoyancy aid is ideal for sailing and I prefer this type myself. They provide some warmth and are not too intrusive yet always work as buoyancy without your action and you can work yourself to rescue yourself. this is obvious from their use as dinghy LJ and Kyaker's LJ where you expect to go in the water and expect to rescue yourself and the boat.
I think the concern about clothing is not so much its weight but the way it restricts your ability to swim to keep afloat.
Regarding your own weight. It is all a question of amount of fat you carry. Fat floats, muscle doesn't.
So I have noticed that when I was young and skinny I had a lot of trouble swimming and floating. Now with another 20Kg of fat it is far easier.
Ultimately you should try getting in the water. Yes I know it is cold. Perhaps a heated pool. My theory is that you need experience at actually falling in. ie the shock of hitting the water and the cold shock should be familiar to you to enhance your ability to recover. Plus of course you need confidence that you can swim and get back on the boat. This I think should enhance your ability to survive. I have fallen off once and nearly off another time both while moored. It is easily done. good luck olewill

 

[Pleiades]

That sinking feeling?

Hi Dylan; personal flotation device capabilities have been extensively researched by many national and international maritime bodies over the years so no need for a practical boat owner icy dip to test for yourself. Our Euro CE certification blurb is as good as it gets. Holding onto anything with 50 Newtons of "lift" will stop one sinking for a while and a coat (or better still a waistcoat) with 50 Newtons will improve initial prospects - particulalry by improving tolerance to the otherwise potentially fatal cold water immersion shock in low water temperatures such as UK - when a casualty gasps and hyperventillates swallowing sea water involuntarily. Rescue/recovery must be rapid however as cold will quickly reduce ability to keep head above the water and heat loss will be quicker if trying to swim to keep upright. The European Standards are comprehensive and worth a skim.
A 50 Newton "buoyancy aid" only provides support for conscious competent swimmers who can help themselves in sheltered water where help is close at hand.
The European Standard now (wrongly in my view) classes a 100 Newton device as a "lifejacket" although that only gives a "reasonable assurance of safety from drowning in calm water".
Proper lifejackets are the 150, 275 or 290 Newton jobs - the inflation in inflation figures is due to the proven failures of 150 Newton jackets to do their job if the casualty is wearing heavy waterproof clothing - boots, carrying kit etc. And all the proper lifejackets must have leg straps and a sprayhood if they are to give best chance of survival in extremis.
The reputable manufacturers all work to the CE categories - try crewsaver.co.uk - you can download their catalogue which sets out the categories in full. And this is just the certification regime for leisure boaters - the professional/commercial kit comes under SOLAS approval with double chambers, double gas cylinders etc. It is a serious business keeping ones head above water...... long may we all continue to do so!
Robin
Pleiades of Birdham
MXWQ5

 

[BarryH]

A PFD kept a friend of mine afloat and he's bloatier than you by a fair margin. I doubt wether how high you float in the water is a factor here. I'd be more worried with water temp and the fact that the tides on the Humber would have taken you a fair way from the boat in no time at all.


I don't sail in the winter, as yet, but do get the kayak out more often. My PFD keeps me afloat and mobile enough to get back into the kayak with little problem. A PFD should be fine for you

 

[Halo]

It depends on how rough the sea is when you are in there. Even a "proper" life jacket may not save you if there are waves in your face and you dont have a spray hood fitted.
Nothing wrong with wearing a buoyancy aid but IMHO its worth wearing the best lifejacket you can in adverse conditions. If you cannot afford a lifejacket I respectfully suggest you stay on the pier or be a fair weather sailor.

 

[Iain C]

I would be amazed if they were selling PDFs for big blokes that would allow me to sink

I've tried this. It's hopeless. It disintegrated at the first sign of water and the ink ran too. I'm going to try a word document next and see if that's any better...

 

[FishyInverness]

Proper lifejackets are the 150, 275 or 290 Newton jobs

Just to clarify: The rating for air inflation jackets is only 150 or 275, there is no 290 rating. Most jackets exceed the rating, so a lot of manufacturers/retailers decide to advertise their jackets as a a newton figure that hasn't been classified (GF Lifejackets inflate to 168 newtons typically, but they are still classed as a 150n) - but it remains that they're either 150n or 275n.

The human body only needs a very small about of buoyancy, only around 20newtons, to remain floating on the surface of calm water - the remainder is about keeping you above it, mouth and nose free of the water, turning you on your back, and so forth.

PS, Iain C - Very dry, very funny!

 

[dylanwinter]

and there you have it

It depends on how rough the sea is when you are in there. Even a "proper" life jacket may not save you if there are waves in your face and you dont have a spray hood fitted.
Nothing wrong with wearing a buoyancy aid but IMHO its worth wearing the best lifejacket you can in adverse conditions. If you cannot afford a lifejacket I respectfully suggest you stay on the pier or be a fair weather sailor.

great advice

I shall stop sailing and concentrate on hitting the right keys in the right order

Dylan

 

[NUTMEG]

Still here...

...thanks to my old Crewsaver dinghy BA. Seriously it saved my life (film of the unhappy event on movie page of my bloggy thing). I wear a proper life jacket with all the bells and whistles while sailing but use the old buoyancy aid in the tender. 13 stone, wellies, winter clothes, hat etc, the BA kept me afloat, gave me time to recover from the cold shock and work out what to do next. Without it I don't think I could have done anything to be honest.

Steve

 

[duncan99210]

They do what they say on the tin: buoyancy aid are an aid to floating, lifejackets are there to provide enough buoyancy in more or less the right place to keep your head above water. If you are confident of being able to keep swimming whilst wearing a BA until you are either rescued or get back in your boat, then wear a BA. If there are any doubts about that, IMO you should wear a lifejacket.

 

[maxi77]

Dylan, You will float even without a buoyancy aid! (Just try swimming to the bottom of the river/pool and trying to stay there.)

As has already been said, the issue is keeping your mouth and nose out of the water. If you are incapacitated, you need a lot of buoyancy, and to be flipped onto your back. Unfortunately, the bulk and position of the buoyancy needed to achieve this will make it very diffcult to swim, or to climb a ladder, etc..

I would prefer a small foam buoyancy aid inshore. At sea I use a manually triggered gas lifejacket. If I found myself in the sea, I wouldn't plan to inflate it unless I had exhausted the possibilities of swimming and self-recovery or helping someone get me back in the boat. The downside of this strategy is that if I am knocked overboard unconscious it won't help me until (and if!) I come round.

I do have an old lifejacket, which is a hybrid - it has enough foam in it to serve as a buoyancy aid (albeit a bulky one), and it has a mouth inflated bladder which takes it up to lifejacket standard.

Not exactly true, most people have positive bouyancy but a few do sink without assistance. Also you lose your bouyancy as your body is compressed by depth, when you get to 100 feet most people are quite negative and I have seen people without weight belts walk around the botton of a 100ft deep tank.

 

[dylanwinter]

My thnking

They do what they say on the tin: buoyancy aid are an aid to floating, lifejackets are there to provide enough buoyancy in more or less the right place to keep your head above water. If you are confident of being able to keep swimming whilst wearing a BA until you are either rescued or get back in your boat, then wear a BA. If there are any doubts about that, IMO you should wear a lifejacket.

given the sort of sailing that I do - up rivers or estuaries, usually solo, the times when I am likely to need the protection is when going along the foredeck to depoy or recover an anchor, when putting out or removing the fenders and sometimes when hanging over the bow with the camera on a tripod

I do sometimes do coastal hops of a day which will get me 5 or six miles from shore but I will never have to venture out along the foredeck.

It does seem to me that the self-inflators are not pareticularly durable and in a self rescue situation I might stand a better chance of getting back aboard or swimming to the nearest shore wearing a dinghy vest than a self inflator.

Up until now I have bene using self-inflators on my journey and felt completely safe in them. Confident that they are really likely to fire off when needed

but having seen the videos of the failures to fire, or the bursting of the bladders I am now not so sure about them

I wite for an American sailing magazine that is aimed at small boat sailors

They all wear faom PFds.

In America you have to have a pfd for every person on board.

If you have four aboard not wearing life jaceks thenthen you must have four solid pfds available.

if people choose to wear a self inflator that counts towards the total - but only if you are wearing it

Four self-inflators hanging in a locker does not cover you when it comes to fining people.

Although I hear what you say about buying the best..... I am no longer convinced that for my sort of sailing the best is actually the best

some-one somewhere should write something about this

Dylan

 

[Malish]

Not exactly true, most people have positive bouyancy but a few do sink without assistance. Also you lose your bouyancy as your body is compressed by depth, when you get to 100 feet most people are quite negative and I have seen people without weight belts walk around the botton of a 100ft deep tank.

By 'ek if a wave puts me down that deep I reckon that Neptune has got me with or without a LJ / BA