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Welcome aboard.� What do you mean you're scared?� Of course you're scared.� What are you complaining about?� Sure you're crammed in here, your legs overlapping your mates' as you bask in your regulated, sumptuous four square feet of alloted space.� Sure you feel like barfing because this raft stinks and feels like riding a jellyfish roller coaster.� Sure you're cold.� But hey, that's why it's called survival: to remain alive or in existence.� That's it.� Bare bones.� Get used to it.� Think where you'd be without any life raft or boat.�
You thought it would be better than back in the boat?� You thought that when you pulled the raft rip chord maybe a brand new forty-foot cutter would pop out?� Get real and be thankful skipper wouldn't let you bail out until you could "step up" to the raft so you could at least get that radio message off and gather the most gear.��
Fortunately, the conditions are now relatively calm, so it wasn't too hard to get the 100 pound four man raft overboard.� It would have been nicer had the raft been lighter and smaller, but this raft is more heavily built.� Since each case is unique, all safety equipment manufacturers try to satisfy the mutually exclusive aims of making the gear the simplest, most fool proof, lightest, and smallest possible while providing the most features, covering every conceivable contingency, and being as commodious as the Queen Mary.� Most good, heavily built and well equipped rafts, especially those approved by SOLAS or the Coast Guard, must be rather large and bulky.� But in rougher conditions, I don't know if we would have gotten her over in time.�
We were also lucky not to have lost it when the boat got rolled in the worst of the weather, since it was cradled on deck, totally exposed to the sea.� Luckily the cradle was heavily built and securely through bolted, but the raft and auxiliary gear would be more secure in a handy deck locker set flush into the hull or cockpit.� That best protects the raft from long-term environmental damage too, but next best is our fiberglass canister in its heavy stainless rack.� Soft valises offer the least resistance to raft damage.� If the locker was near the boat's perimeter, like the lazarette with a door through the transom, we could have deployed even a heavy raft and gear with a single yank of a lanyard.�
What if we couldn't get the raft off before the boat went down?� A hydrostatic release would have let the raft go, but if we got rolled or overwhelmed by a huge wave, the water pressure might release the raft prematurely.� A hydro release or not a hydro release?� That is just one of the questions.
Pre-attached long tethers join our raft to emergency equipment ditch kits, or "going away bags," as a friend calls them, which allowed us to deploy heavy bulky raft first and then the bags while preventing their separation and loss.��
So here we are.� Let's face the music.� We can die of a lot of things: (a) fear, hypothermia (exposure), and physical injury, which can kill in minutes to hours, even in relatively warm waters, (b) dehydration, which can kill in days (about 10 average), and (c) hunger, which can kill in weeks (about 30 days).�
The raft itself won't heal, water, or feed us.� It's only the base requirement: a shelter and platform from which we can use our all important survival tools.� Right now it's cold.� If our raft has a single-skin, non-inflated floor, I hope we salvaged air mattresses or cushions on which to sit.� A raft with an inflated floor provides insulation and protects us from bumping fish and sharks when we get tender salt water sores.� A removable air pillow type floor allows water to drain away from us to help prevent sores and heat loss.� If need be, we can lift it to repair it or the floor.� A built in inflated floor prevents a leak if the bottom or top alone is holed.� In any case, there are no long-term survival voyages in cold waters, so I hope we have survival or immersion suits, or at least space blankets and chemical heat packs.
The raft canopy helps keep us warm and protects us from the sun.� This one is sealed all around except the opening, reducing ventilation in good weather.� The single entry impeded boarding compared to an open, roll-up type canopy but some roll-ups are not secure enough to face hard weather.� What's that?� Damn, must be a trough.� The weather is worse than ever and now we're flying around.� It's like being in a continuous auto accident.� Whether the canopy is a roll-down type or fixed, it must be glued and taped to the inflation tubes all around or jets of water are going to force their way in here and rip the thing apart.�
Thank God for good entry port and other seam closures too--double sealed, zippered tight, and with sewn back-up ties.� Little velcro closures have been cursed by survivors since the Baileys' 119 day drift in 1972.� A breeze can blow a velcroed entry closure open.� Glued-on ties rip off.� If waves toss you or your gear out, or if they leave you awash and steal your heat, you can start listening for the end-of-your-life alarm.� We have tied all the gear in haven't we?� The raft does have good handholds and secure attachment points, right?� Okay, hang on.
Now don't freak out if this thing capsizes.� We can right it, and with some practice we can reright it without getting out.� But we want to stay upright if we can.� Stop arguing over what's the most stable raft--the huge Givens ballast bag, the Switlik doughnut-like torroidal system, or the common multiple ballast bags.� Raft stability depends on a lot of factors.
Beginning in 1978 NMI (National Maritime Institute, renamed British Maritime Technology Ltd. or BMT) in the United Kingdom began stability tests on life rafts, including wind tunnel tests on model waves and model rafts in wind/wave tanks for winds to hurricane force.� These were followed by sea trials in conjunction with the Icelandic government in winds reaching Force 9, then more model tests and finally more sea trials.� Although each program had its limitations and none included the Givens ballast bag or Switlik torroidal systems, the tests included many manufactures, shapes, canopy styles, and ballast systems.� Results of all the tests reinforced one another.� We can only interpolate results as they relate to rafts in general, and hope for further comparative testing.
Both waves and wind cause capsize of life rafts.� Water ballast pockets help resist capsize--the more the merrier--but this is not the complete answer.� Raft shape, wind under the floor, canopy shape, loading of occupants, water ballast, and sea anchors all influence stability.
Bows of square and rectangular rafts tend to dig in on the face of steep waves, particularly as the windward side of the raft lifts.� Our raft is round and slides forward easier.� Then again, it only allows one of us to stretch out flat in the center whereas the rectangular raft allows several of us to lie side by side when conditions moderate.�
To help stabilize the raft, let's all huddle up here and hang onto the secure handholds on the windward side, lifting the bow more and preventing the now screaming wind from getting under the floor and flipping us.�
The wind is also trying to make the canopy into a spinnaker.� Don't let the windward side belly up to create overturning lift.� It's also a good thing the sea anchor attachment is opposite the entry port so the entry faces downwind.� Otherwise wind and breaking waves can attack the entry.� If they break through, the wind will turn the canopy into an overturning sail, and breaking waves will fill our cave, steal our heat, steal our gear.� Right now we enjoy the low rounded profile of the canopy support tube that reduces our windage.� In calmer seas we'd prefer higher, squarer canopy support tubes so more of us can sit up.� The Switlik coastal canopy offers some options.� Ends are secured to the tubes to provide reasonable security in heavy seas, but in lighter going the midship canopy can be completely removed and the ends rolled down in various combinations to provide ventilation, work space, or, with only one end erected, sail area.��
NMI and the Icelandic government found that the best normal water ballast pockets were triangular in section and usually weighted to promote quick filling.� Many ballast pockets still failed and, "Of the six rafts put into the water, only those on which sea anchors remained operational did not capsize."� The last test showed, "the sea anchor was a powerful stabilizing force and could prevent the life raft from capsizing even when the ballast pockets were destroyed."�
Not just any sea anchor, however.� Most are dogs.� The improved sea anchor is a tapered sleeve, at least twice as long as the mouth is wide and the tail a third the mouth's diameter.� If it's made of porous mesh it doesn't need a swivel and the mouth should be stiff and open to promote quick filling.� Flat cloth parachute types and cones spin, so require swivels and tend to foul themselves by tumbling forward in breaking waves, which fouls their bridles.� NMI found that mesh or laces sewn around the sea anchor bridle prevented sea anchors from fouling themselves.� A new possible option is the series drogue, which is a string of smaller cones that reduce shock loads by evening out the sea anchor's pull over numerous waves aft.� In any case, that sea anchor rode, swivels, and attachment point on the raft had better be tough because the snatch loads in even moderate conditions can be eight or nine times the anchor's steady pull.
Numerous raft styles with varying water ballast have survived upright in blows exceeding 80 knot winds and 30-foot waves.� The heavily ballasted Givens raft resisted wind gusts to 170 knots and 35-foot seas when survivors were forced under water numerous times and the tubes began to separate.� Who knows if what other rafts could survive such conditions.� All types, including the Givens, have been knocked down to 90 degrees in waves of only 15-feet.� In addition, "over large ballast pockets can place a great strain on the raft structure leading to a need to strengthen it, with a consequent increase in weight and cost.� Also, an already uncomfortable motion is made much worse on a raft carrying too much ballast." (Testing of life rafts in U.K. by E.J. Foreman, BMT)� Proponents of heavily ballasted rafts continue to debate this view.� I only know that riding a life raft of any kind is hellish in a gale, all have suffered failures, and being capsized is only one of numerous worries for survivors and is not in itself necessarily critical.� The records for distance and time afloat go to much more lightly ballasted rafts.
It is moderating?� Most of a long survival voyage is spent drifting slowly in moderate weather.� The EPIRB hasn't brought help so why not get the hell out of here?�
Now our big ballast bags are a real drag and we wish the canopy would open up more.� Cut the ballast off?� Why have it to begin with then?� And what about the next blow?� Tie the bags up?� Okay, best we can do.�
It certainly would be nice to have a completely different kind of raft now, what the French call a "Dynamic" raft, meaning the thing sails.� The last time I lost my boat, had I been able to beam reach, I could have shortened my drift from 1,800 miles to 450; had I been able to sail even dead downwind but increase speed to a moderate 2.5 knots, I would have been afloat 25 days rather than 76; had I been able to do both I would have sailed to safety in a mere six or seven days.
Some lucky survivors escape with a dinghy or inflatable sport boat.� With two boats, survivors can fan out, work and rest more efficiently, and set sails to make real headway.� A dinghy should be unsinkable or have watertight compartments, maybe even have its floatation augmented by fenders secured to the outside.� It should also carry additional emergency gear, tarps, sea anchor...�
Personally, I wish for a life raft shaped like a sport boat, but wider, with a high bow to resist pitchpoling, a retractable ballast system, and a reasonable rig or kite sails for propulsion, but most ocean disasters involve aircraft, commercial shipping, and oil rigs, not voyaging yachts, so most bureaucracies promote stability of position to assist SAR (Search and Rescue).� If you want a good sailing lifeboat that can be carried on a small yacht, you'll have to create it.
Why is this bottom tube soft?� Leaking already?� I hope we have some good repair clamps.� Those glue patches that say "Material should be dry prior to application" are as cruel a joke as the fishing kit that consists of a fifty foot piece of string and a hook.� Why didn't we look closer at the equipment that came with the raft?� Good thing we got our own gear.� Also good thing that most life rafts have two separate inflation chambers.� Still, with the bottom one collapsed, water forces distort the shape and we sink very low in the water.� It's like living in rubber quick sand.� If we can't fix it, we'll die.� Can you blow up the raft by mouth?� Most good valves require a pump.� What about the pump itself?� Is it easy to use?� Have we got a spare in case it breaks or is lost?
In single inflation chamber rafts, a hole is disastrous.� Some rafts have inner safety tubes, however.� Switlik's single tube coastal raft is divided by inner socks that are forced by air pressure from the secure side into the damaged half of the tube as air escapes.� The Butlers lived happily in this kind of raft for 66 days in 1989.� Well, maybe not happily.� But in most single tube rafts, or sport boats, if you get a leak you've got a problem that can ruin your whole life.�
It finally rains.� We're smart enough to carry a reverse osmosis pump but rain will allow us to drink more, build our stock, and wash to heal our sores.� Canopy gutter systems are a bonus.� Some canopies still break down in time, making water undrinkable.� You can't be sure when they're new.� We do have plastic sheets or space blankets to catch water and containers to store it, don't we?�
Oh goody.� Here comes our ride.� But it's night.� I'm glad we have good flares, the hand-held VHF, and a lot of nice reflective strips on the outside to attract the ships spotlight.
It goes without saying that we hope your raft is well made, but construction is beyond our scope here.� Talk to raft service people who see the best and worst, keep up with materials and construction technology, and see what makes have to be fixed the most frequently.� Your raft can really only help keep you warm and secure in cold and rugged seas and give you a third chance if it is damaged.� I hope future rafts or secondary craft will promote mobility as well.� The rest of survival, the food, the water, is up to you and your equipment.� A good raft will put you in the mood, however.� It'll reassure you, shut down the panic, make this voyage fun!� Well, almost.��
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Publisher and Editor: Doug Ritter
Email: Doug Ritter
URL:
http://www.equipped.org/callahan_life_raft1.htm
First Published on ETS: November 2, 2001
Email to: [email protected]
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