dry-suit or liferaft?
I suspect that those who have been immersed in cold water would put the dry suit first.
Well with the benefit of (military) experience.....You can guarantee getting into the dry suit,..assuming you put it on before you go flying.... but despite all your preparations and training you can never ever guarantee getting into the dinghy... it may not inflate, and even if it does you might not have enough strength / feeling in the hands left to climb into the thing.
If you have a working PLB/ELT the SAR guys will get very close to you, even at night, but don't underestimate the simple stuff such as reflective strips and salt water powered lights
And as Syllo.....
said
Unless you've had first hand experience of sudden exposure to cold water, you are extremely likely to greatly underestimate its effects
Watching a liferaft exercise off Moray coast
From my living room window, I saw a guy trying to get into a liferaft in choppy water, with the Lossie rescue helicopter standing by. Every time he got in, he was soon tipped out. Eventually, he stayed in long enough to satisfy the crew. The winchman came down, and was lifting him up, when the line lowered again. It looked like the winchman dropped into the water. A few strokes took him to the raft. One movement put him in it. He then relaxed, and drifted out of sight under the cliffs.
I assume the first guy was fit, and had pool training. He made it look impossible. The second guy made it look easy. Both would have had survival suits.
I assume the first guy was fit, and had pool training. He made it look impossible. The second guy made it look easy. Both would have had survival suits.
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cut to the chase:
any hard info /references on survival times/rates in the irish sea/english channel at varying seasons of the year?
is there any time of year where a PLB and lifevest alone are sufficient to last until rescue arrives? such that after those conditions are exceeded, a suit or raft are de rigeur.
any hard info /references on survival times/rates in the irish sea/english channel at varying seasons of the year?
is there any time of year where a PLB and lifevest alone are sufficient to last until rescue arrives? such that after those conditions are exceeded, a suit or raft are de rigeur.
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cut to the chase:
any hard info /references on survival times/rates in the irish sea/english channel at varying seasons of the year?
is there any time of year where a PLB and lifevest alone are sufficient to last until rescue arrives? such that after those conditions are exceeded, a suit or raft are de rigeur.
any hard info /references on survival times/rates in the irish sea/english channel at varying seasons of the year?
is there any time of year where a PLB and lifevest alone are sufficient to last until rescue arrives? such that after those conditions are exceeded, a suit or raft are de rigeur.
If you use Google you will find plenty of on-line material about cold water survival times.
Hmmmyeah
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On the subject of lifejackets, as raised by hhobbit, it's entirely possible, quite likely even, to drown whilst wearing one.
If it's not fitted with crotch straps, you'll run out of energy to hold yourself high enough in it to keep your head above water long before you succumb to hypothermia. If it's not equipped with a spray hood, you'll drown due to the quantity of water you inhale as it splashes across your face.
It's not merely a case of carrying pieces of kit. They have to be the right pieces of kit, fitted with the right accessories, you have to know how to use them correctly and be familiar enough with them to do so blindfold and one handed. It also helps immesurably to understand your adversary, the sea.
Once again, I suggest reading Essentials of Sea Survival. It will answer all your questions and more and put you in the picture as to just how serious an event ending up in the drink actually is.
At sea, even if you ditch successfully you've just become a victim. It's only when you're picked up from the water and have made it through the next few hours that you become a survivor.
If it's not fitted with crotch straps, you'll run out of energy to hold yourself high enough in it to keep your head above water long before you succumb to hypothermia. If it's not equipped with a spray hood, you'll drown due to the quantity of water you inhale as it splashes across your face.
It's not merely a case of carrying pieces of kit. They have to be the right pieces of kit, fitted with the right accessories, you have to know how to use them correctly and be familiar enough with them to do so blindfold and one handed. It also helps immesurably to understand your adversary, the sea.
Once again, I suggest reading Essentials of Sea Survival. It will answer all your questions and more and put you in the picture as to just how serious an event ending up in the drink actually is.
At sea, even if you ditch successfully you've just become a victim. It's only when you're picked up from the water and have made it through the next few hours that you become a survivor.
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The 'definitive' reference study for offshore workers is http://www.hse.gov.uk/research/otopdf/1995/oto95038.pdf.
The summary numbers are: 5 deg C less than force 3 with an immersion suit and suitable clothing - 2 hours, more than force 3 - 1 hour.
5 deg C with 1 litre of leakage into suit, les than force 3 - 80 minutes, more than force 3 - 40 minutes.
15 deg C - 6 hours.
Cold shock - no way of telling, or rather calculating it, but 'a significant risk of drowning' within the risk minutes.
From the personal experience of someone I know - hands 'useless' after 10 to 15 minutes without the insulated gloves (he lost them!)
The summary numbers are: 5 deg C less than force 3 with an immersion suit and suitable clothing - 2 hours, more than force 3 - 1 hour.
5 deg C with 1 litre of leakage into suit, les than force 3 - 80 minutes, more than force 3 - 40 minutes.
15 deg C - 6 hours.
Cold shock - no way of telling, or rather calculating it, but 'a significant risk of drowning' within the risk minutes.
From the personal experience of someone I know - hands 'useless' after 10 to 15 minutes without the insulated gloves (he lost them!)
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Many years ago I took part in a one-week survival research exercise jointly run by Plymouth Poly and Jersey. I was an BCU coach at the time and acted as an instructor and assisted organising safety boats etc. One of the exercises was to take 30 odd 18 – 19 year old students, give them a full detailed briefing on getting into a raft, and the exercise. Take them out in a safety boat (dressed in light clothing), dump them in the water alongside a fully inflated 4 – 5 man raft and see what happened. This was the summer, and we were a few miles off shore. None of the “ordinary” students got in, the small number with extensive and recent experience all did.
Based on this and my Sea Canoeing experience I think it is extremely unwise to assume you will get into a raft in open water unless you really know what you are about. It is 20 years since I last did an open water dingy drill and I am not at all sure I could do it for real after all that time. I work very hard on avoiding long over water crossings (even flying the short crossing and down the coast). The short crossing in my aircraft is an acceptable risk as I am only out of gliding range for 90 sec, but even in summer, going down in say the north sea, would be very bad news.
Rod1
Based on this and my Sea Canoeing experience I think it is extremely unwise to assume you will get into a raft in open water unless you really know what you are about. It is 20 years since I last did an open water dingy drill and I am not at all sure I could do it for real after all that time. I work very hard on avoiding long over water crossings (even flying the short crossing and down the coast). The short crossing in my aircraft is an acceptable risk as I am only out of gliding range for 90 sec, but even in summer, going down in say the north sea, would be very bad news.
Rod1
As a driver would I drive in poor vis with only so-called sidelights on as opposed to dipped beam to ensure I'm seen? No. I don't believe in half measures. As a diver with over 400 dives in our cold seas, would I fly over water in an immersion suit as opposed to a lightweight drysuit with a good quality undersuit which I know will keep me alive for much much longer? No. I don't believe in half measures.
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A dry suit and an immersion suit is principally the same thing, although the names are used in different contexts. It's essentially a waterproof coverall with watertight neck and wrist seals, and ankle seals or integrated socks/boots. The idea is that you wear sufficient layers of insulating stuff underneath (for instance a "bear suit", essentially a fleece coverall) to keep you warm, while the outer shell keeps the water out.
A wet suit is a neoprene suit, somewhere between 3 and 15mm thick, which is NOT watertight. Instead, what it does is trap water between your skin and the suit, with that layer of water plus the suit itself providing some insulation. Wet suits are typically much tighter around your body, much cheaper, and easier to move around in than dry suits, so they're the choice for divers, surfers, dinghy sailors etc. who operate in reasonably warm water conditions. Furthermore, in diving, a wet suit is easier and safer to operate than a dry suit so a wet suit is what divers use in the beginning of their career - or even their whole career if they just dive in tropical waters.
The term "dry suit" is typically used in the diving world to contrast with the word "wet suit". The term "immersion suit" is usually used in offshore operations where nobody enters the water voluntarily.
Of course, due to the different requirements a divers "dry suit" will have different features than an offshore "immersion suit". A divers dry suit for instance will normally not have pockets, no integrated boots (because you need to be able to put your fins on) but will have vents and an air hose connection to compensate for the increasing pressure at depth. An immersion suit on the other hand will (should) have pockets, and may be constructed differently because it's normally worn in a seated position.
A wet suit is a neoprene suit, somewhere between 3 and 15mm thick, which is NOT watertight. Instead, what it does is trap water between your skin and the suit, with that layer of water plus the suit itself providing some insulation. Wet suits are typically much tighter around your body, much cheaper, and easier to move around in than dry suits, so they're the choice for divers, surfers, dinghy sailors etc. who operate in reasonably warm water conditions. Furthermore, in diving, a wet suit is easier and safer to operate than a dry suit so a wet suit is what divers use in the beginning of their career - or even their whole career if they just dive in tropical waters.
The term "dry suit" is typically used in the diving world to contrast with the word "wet suit". The term "immersion suit" is usually used in offshore operations where nobody enters the water voluntarily.
Of course, due to the different requirements a divers "dry suit" will have different features than an offshore "immersion suit". A divers dry suit for instance will normally not have pockets, no integrated boots (because you need to be able to put your fins on) but will have vents and an air hose connection to compensate for the increasing pressure at depth. An immersion suit on the other hand will (should) have pockets, and may be constructed differently because it's normally worn in a seated position.
For the person who was doubtful about the usefulness of a PLB when not in a raft -- PLBs generally are waterproof and float.
That said, overwater I want it tethered to me and yes the 406/121 MHz antenna wants to be pointing up as well as the GPS antenna.
That said, overwater I want it tethered to me and yes the 406/121 MHz antenna wants to be pointing up as well as the GPS antenna.
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RBF, not all PLB's float. If I remember correctly the latest McMurdo ones don't. I read that somewhere, but can't remember where, so can't remember how reliable that is.
I also read the results of some tests, which showed that they actually produced very unreliable results (taking many hours to get a fix) if they weren't held out of the water. Some in the test never got a fix.
Of course they still transmit on 121.5 to help S&R get close to you. I don't have time to look now, but I think those tests were on equipped.com
dp
I also read the results of some tests, which showed that they actually produced very unreliable results (taking many hours to get a fix) if they weren't held out of the water. Some in the test never got a fix.
Of course they still transmit on 121.5 to help S&R get close to you. I don't have time to look now, but I think those tests were on equipped.com
dp
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As a driver would I drive in poor vis with only so-called sidelights on as opposed to dipped beam to ensure I'm seen? No. I don't believe in half measures. As a diver with over 400 dives in our cold seas, would I fly over water in an immersion suit as opposed to a lightweight drysuit with a good quality undersuit which I know will keep me alive for much much longer? No. I don't believe in half measures.
So immersion suits are no where near as good as wetsuit/undersuit combo?
UK sea temps:-
UK Sea Temperatures
So immersion suits are no where near as good as wetsuit/undersuit combo?
Immersion or Flotation suits are bulky, Mr Blobby affairs which may or may not be entirely waterproof. Not suited to a cramped cockpit.
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Technically:
An immersion suit is a thick suit with built in boots and gloves designed to be both waterproof and provide insulation. They are primarily provided on board ships and rigs for evacuation. They will keep you alive for an extended period if immersed, but offer virtually no dexterity. They are of no use to pilots
A survival suit is a water tight membrane suit, generally of breathable fabric which have built in socks and seals around wrist and neck. Insulation layers are required to provide protection from the cold. Worn by professional pilots who spend extended periods over the sea.
Dry suit, worn by divers, other water sports enthusiast and rescue services. Maybe breathable, but probably of heavier fabric than a survival suit. Sweaty and may restrict dexterity.
Wetsuit, insulated neoprene suit that allows water ingress via neck, wrist and ankles, but attempts to trap that water and allow it to be warmed by body temperature. Of little use in survival scenario since any wave action will tend to pump cold water into the suit.
THe best solution to the PLB problem is a PLB stowed in a pocket on the lifejacket belt, with its antenna clipped to the stole. Activate and will work without further intervention, ideal if you loose consciousness.
An immersion suit is a thick suit with built in boots and gloves designed to be both waterproof and provide insulation. They are primarily provided on board ships and rigs for evacuation. They will keep you alive for an extended period if immersed, but offer virtually no dexterity. They are of no use to pilots
A survival suit is a water tight membrane suit, generally of breathable fabric which have built in socks and seals around wrist and neck. Insulation layers are required to provide protection from the cold. Worn by professional pilots who spend extended periods over the sea.
Dry suit, worn by divers, other water sports enthusiast and rescue services. Maybe breathable, but probably of heavier fabric than a survival suit. Sweaty and may restrict dexterity.
Wetsuit, insulated neoprene suit that allows water ingress via neck, wrist and ankles, but attempts to trap that water and allow it to be warmed by body temperature. Of little use in survival scenario since any wave action will tend to pump cold water into the suit.
THe best solution to the PLB problem is a PLB stowed in a pocket on the lifejacket belt, with its antenna clipped to the stole. Activate and will work without further intervention, ideal if you loose consciousness.
Hmmmyeah
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Excellent synopsis on suit types by Droopystop.
I possess an immersion suit and it's not a garment you're going to do much whilst wearing aside from bob around in the drink. It's constructed of 10mm flame retardent neoprene and has thick rubber gloves which provide very little dexterity sewn and taped into it and 10mm neoprene mittens to go over these. It's hot, cumbersome and weighs a ton. It takes between one and two minutes to don after practice. No good for aviation use.
A survival suit of the type Droopystop mentions is the kind of thing SAR crews use and is wearable for long periods and doesn't restrict movement. In essence, it's a (usually) gore-tex boiler suit with sewn in gore-tex 'socks' and rubber neck and wrist seals. It provides no insulation in its own right, so what you wear underneath will determine how long you last in cold water. These types of immersion suit typically leak a reasonable amount once you're in the water. Usually not enough to cause major problems in its own right, but the psychological effect on the victim can be immense. They think their suit is failing, they worry that they're getting wet and going to get cold and panic that the ingress of water will result in them being dragged down by the suit. As a result, they're likely to move around in the water more, thus increasing the problem of leakage and, in addition, wasting energy and body heat. This sort of suit is however wearable for flying and probably the best compromise unless you're prepared to fly in a full diving drysuit. Remember though, the weak link is the amount of insulation you have beneath.
One item I've used in anger in the water is an enhanced survival suit made for sailing. It's a one piece gore-tex suit made as extreme weather sailing wear with neck and wrist seals and boots built in. It's of superior design and construction than a regular survival suit as it's made for an environment where a trip into the water is a much more of a likelihood. The advantage it has over a conventional survival suit is that it has an oral inflation tube. If you end up in the water, you inflate the suit so that it, and the surrounding cold water, is not pressed against the body, greatly reducing the rate at which your body temperature falls. I can vouch for the fact that these work extremely well. They cost £1000, but for winter and cold climate offshore sailing I wouldn't be without one. There's no reason they shouldn't be used as a superior alternative to a conventional survival suit for flying purposes.
Whatever you're wearing, if you do end up in the water, the best position to be in whilst in cold water is with your knees pulled up to your chest and you arms wrapped round your torso above and inside your knees. This is the HELP (Heat Escape Lessening Posture) position and makes a huge difference to the rate at which your body temperature falls. Additionally, if wearing a survival suit, it keeps you still in the water thus preventing further leakage and allows any water already inside the suit to remain still against your skin and thus be warmed by it. If there are numerous people in the water they should adopt this position individually then group together in a ring formation dropping the knees to allow closer contact between individuals.
Finally, re PLBs. A PLB has no requirement to float or, even if it does happen to do so, to transmit correctly whilst doing so. An EPIRB, however, is required to do both. It's very design function is that it floats in an upright position in which the aerial is clear of the water and able to transmit adequately. Most also contain a high-intensity strobe light for final pinpoint location. The two are very different things in their effectiveness - don't confuse them.
Also, be aware that in personal beacon terms 121.5MHz is only used as a local homing signal now. The Cospas-Sarsat satellite system ceased listening on this frequency in Feb 09. The system now listens on 406MHz only. Old beacons which transmit only on 121.5/243MHz are essentially obsolete.
I possess an immersion suit and it's not a garment you're going to do much whilst wearing aside from bob around in the drink. It's constructed of 10mm flame retardent neoprene and has thick rubber gloves which provide very little dexterity sewn and taped into it and 10mm neoprene mittens to go over these. It's hot, cumbersome and weighs a ton. It takes between one and two minutes to don after practice. No good for aviation use.
A survival suit of the type Droopystop mentions is the kind of thing SAR crews use and is wearable for long periods and doesn't restrict movement. In essence, it's a (usually) gore-tex boiler suit with sewn in gore-tex 'socks' and rubber neck and wrist seals. It provides no insulation in its own right, so what you wear underneath will determine how long you last in cold water. These types of immersion suit typically leak a reasonable amount once you're in the water. Usually not enough to cause major problems in its own right, but the psychological effect on the victim can be immense. They think their suit is failing, they worry that they're getting wet and going to get cold and panic that the ingress of water will result in them being dragged down by the suit. As a result, they're likely to move around in the water more, thus increasing the problem of leakage and, in addition, wasting energy and body heat. This sort of suit is however wearable for flying and probably the best compromise unless you're prepared to fly in a full diving drysuit. Remember though, the weak link is the amount of insulation you have beneath.
One item I've used in anger in the water is an enhanced survival suit made for sailing. It's a one piece gore-tex suit made as extreme weather sailing wear with neck and wrist seals and boots built in. It's of superior design and construction than a regular survival suit as it's made for an environment where a trip into the water is a much more of a likelihood. The advantage it has over a conventional survival suit is that it has an oral inflation tube. If you end up in the water, you inflate the suit so that it, and the surrounding cold water, is not pressed against the body, greatly reducing the rate at which your body temperature falls. I can vouch for the fact that these work extremely well. They cost £1000, but for winter and cold climate offshore sailing I wouldn't be without one. There's no reason they shouldn't be used as a superior alternative to a conventional survival suit for flying purposes.
Whatever you're wearing, if you do end up in the water, the best position to be in whilst in cold water is with your knees pulled up to your chest and you arms wrapped round your torso above and inside your knees. This is the HELP (Heat Escape Lessening Posture) position and makes a huge difference to the rate at which your body temperature falls. Additionally, if wearing a survival suit, it keeps you still in the water thus preventing further leakage and allows any water already inside the suit to remain still against your skin and thus be warmed by it. If there are numerous people in the water they should adopt this position individually then group together in a ring formation dropping the knees to allow closer contact between individuals.
Finally, re PLBs. A PLB has no requirement to float or, even if it does happen to do so, to transmit correctly whilst doing so. An EPIRB, however, is required to do both. It's very design function is that it floats in an upright position in which the aerial is clear of the water and able to transmit adequately. Most also contain a high-intensity strobe light for final pinpoint location. The two are very different things in their effectiveness - don't confuse them.
Also, be aware that in personal beacon terms 121.5MHz is only used as a local homing signal now. The Cospas-Sarsat satellite system ceased listening on this frequency in Feb 09. The system now listens on 406MHz only. Old beacons which transmit only on 121.5/243MHz are essentially obsolete.
Last edited by SyllogismCheck; 18th Jan 2010 at 18:20.
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Originally Posted by gasax
My shiny new McMurdo Fastfind Max G floats!
Don't know about the older ones.
Don't know about the older ones.
I was refering to the Fast find 310. I said the latest one, because that one was released long after the Max G was released.
Looking online, I see that McMurdo make a "boyancy pouch" for the 310 which they sell seperately, which seems to confirm my memory that the unit itself doesn't float.
I too went for the older Max G model, because it floated
Looking at the instructions of my Max G, it seems my recollation of it not working very well in the water was correct too
It says:
The PLB is totally waterproof but is not designed to operate when floating on the surface of the water. It is boyant and will not sink if dropped into water, if possible keep it out of the water when in use, place it high up on your PFD, lifejacket, or chest and clear of any wave wash. Any trapped water should be removed periodically by shaking the PLB.
I found a report on different beacons on the Equipped website.
You can see it here.
406 MHz GPS Enabled Emergency Beacon Evaluation - EQUIPPED TO SURVIVE (tm)
Here is a paragraph from the conclusions
Based on the test results, which proved to be consistent with previous de-identified testing conducted by the U.S. government at which the principal author was present, users of the McMurdo self-locating beacons tested may expect to find that GPS-derived location may not be transmitted unless environmental conditions are generally benign and the beacon is stable, and unless there is a largely uninterrupted sky view covering most of 180 degrees above and 360 degrees around the beacon location. This level of performance appears to be inconsistent with that portrayed in McMurdo's advertising and product literature and consumers' reasonable expectations
I stand by my earlier post. If you want to give yourself a reasonable probability of survival then you probably need both an immersion suit and a life raft. Those argueing for one or the other alone are probably doing the 'easily led' a disservice.
dp
ps. I just fly with a life raft....but I appreciate the risk that I'm taking.
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Technically:
An immersion suit is a thick suit with built in boots and gloves designed to be both waterproof and provide insulation. They are primarily provided on board ships and rigs for evacuation. They will keep you alive for an extended period if immersed, but offer virtually no dexterity. They are of no use to pilots
A survival suit is a water tight membrane suit, generally of breathable fabric which have built in socks and seals around wrist and neck. Insulation layers are required to provide protection from the cold. Worn by professional pilots who spend extended periods over the sea.
Dry suit, worn by divers, other water sports enthusiast and rescue services. Maybe breathable, but probably of heavier fabric than a survival suit. Sweaty and may restrict dexterity.
Wetsuit, insulated neoprene suit that allows water ingress via neck, wrist and ankles, but attempts to trap that water and allow it to be warmed by body temperature. Of little use in survival scenario since any wave action will tend to pump cold water into the suit.
THe best solution to the PLB problem is a PLB stowed in a pocket on the lifejacket belt, with its antenna clipped to the stole. Activate and will work without further intervention, ideal if you loose consciousness.
An immersion suit is a thick suit with built in boots and gloves designed to be both waterproof and provide insulation. They are primarily provided on board ships and rigs for evacuation. They will keep you alive for an extended period if immersed, but offer virtually no dexterity. They are of no use to pilots
A survival suit is a water tight membrane suit, generally of breathable fabric which have built in socks and seals around wrist and neck. Insulation layers are required to provide protection from the cold. Worn by professional pilots who spend extended periods over the sea.
Dry suit, worn by divers, other water sports enthusiast and rescue services. Maybe breathable, but probably of heavier fabric than a survival suit. Sweaty and may restrict dexterity.
Wetsuit, insulated neoprene suit that allows water ingress via neck, wrist and ankles, but attempts to trap that water and allow it to be warmed by body temperature. Of little use in survival scenario since any wave action will tend to pump cold water into the suit.
THe best solution to the PLB problem is a PLB stowed in a pocket on the lifejacket belt, with its antenna clipped to the stole. Activate and will work without further intervention, ideal if you loose consciousness.
so this is a survival suit: and would not be as good as a lightweight drysuit with undersuit like mentioned above.
Typhoon International - Commercial > Aviation Drysuits > Civilian Tofs Suit Blue
Fastfind MaxG McMurdo EPIRB
it says here that this new PLB "significantly reducing the normal search area down from a 28sq nm area, when given a clear view skyward. It also has a visual indication of GPS position acquisition"
28 nm is a massive area!