Boarding Seas

[ebb]

Mike,
Personally don't see how enough foam could be squirelled away in an A/C cruiser to make significant difference. But there's no reason emergency bouyancy bags couldn't be secured inside the boat, placed in a way the inflation of the bags wouldn't hurt or smother an occupant below, and leaving some room to manuever. Maybe the bags could be inflated in a totally swamped situation to void enough water to get the vessel to float on its own again.

[There you'ld be, soaking wet and cold, still alive after the worst night of your life. The bouy bags are keeping the boat afloat at the sheerline, but waves are still washing aboard over the stern into the cockpit. Looking into the companioway there is only water below upto the bridgedeck. You reach in, push a switch and in a series of hisses and whooshes the water below erupts out of the companionway. Instead of water there are tan pillows in the space. Suddenly the boat is floating a foot higher and the raildogs are flopping now but keeping the waves out. You find a snickerdoodle bar in the emergency bag and the sun breaks thru the clouds.]

Check out the site below. Just found it. One comentator described this as 'emerging technology.' The outfit targets small boats and puts the self-inflating airbags down on the spray rail in speed boats. But it certainly is the right idea, my comment being that if the vessels they depict overturn the placement of the bags might float the boat but probably upside down.

Keeping a displacement ocean going sailboat in trouble afloat will require a lot of serious and clever development of a system - but it's an idea that's already here! Nothing new under the sun. I'ld have more faith in the outcome if, instead of this company being in Colorado, they were located in Coronado.

www.goboatingmag.com/main/article.asp?id=3555

[CapnK]

Just some related thoughts -

When I rebuild #370's interior, I'm planning on making all compartments below berth-level able to be sealed off independently of each other. Hopefully, if something pokes through the hull, I'd be able to seal the area long enough to limp into a port for repair. Several ounces of prevention (say about 10oz/sq yd) may well be a lotta pounds of repair, though.

I'm thinking to lay in a sheet of kevlar-reinforced glass (should be spelled with a $$, I think ) against the hull interior from the bow as far aft as I can afford it, from maybe 12" above waterline down. I have a friend who builds surfboards, so I can get the stuff at his cost, which will help.

This is not to make the hull bulletproof, just as a way to help dissipate the shock of striking something outwards fast (which is what kevlar does in the BP vests), to minimize the breadth of any actual punctures. Will it make a huge difference? I don't know. It's a simple thing to do, won't add much weight, will actually lighten wallet. I've seen some of what lurks out on the ocean, on and just below the surface. Scariest thing ever was a 60+' tree trunk with only the stoutest of roots left, poking out from one end. Nothing higher than 2' out of the water, 98% of it was just under. I was on a Hobie, daytime, sighted it perhaps 50 yards away, and was able to swerve in time. Hit that puppy going 5 kts in a seaway and it would not be fun. Pray that you don't find a lost shipping container of Nike shoes or lumber out there at night... Paranoid? Yes, any time in water depth is over deck height.

As far as sealing lockers off, in its simplest form, maybe having pre-drilled holes around the edge of the lockers, and keep fasteners and tool to apply them handy. Some sort of commercial latch may work for this also, I haven't looked yet to see what is available. I'm planning on raising the level of the settee berths to above waterline, perhaps on level with the v-berth surface. I think it unlikely that the aft quarters could be hit strong enough to puncture, but may close off an area under the cockpit floor for a little reserve buoyancy in that area anyway. Forward most compartments would store those things only needed very rarely and/or at anchor, enabling them to remain closed for passages.

[ebb]

Great ideas!
Why Kevlar? Has problems with wet out I hear.
If you will be tabbing your furniture in you'll be adding plenty reinforcement to the hull.

You may have seen Jim (twice around) Baldwin on the Triton page or his own page on this subject. He has given a lot of thought to staying afloat.

[oops, gotta go!]

[CapnK]

Hi ebb -

Kevlar because from what I understand about how it works in BP vests is to take the force of a striking projectile and rapidly transfer that shock outwards along the length of its fibers, instead of allowing the shock to penetrate in.

I'm thinking that if it works with bullets and human chests, it should work to spread the shock load / point load of an impact on a saiboat hull as well, onto other areas of the hull. I'm no engineer, but it seems that if you could unload the impact forces out over a wide area fast, there would be less damage at the point of contact.

Yes, Jim B's pages are awesome. Both his and Glissando's refits served as inspiration for me to start looking for an older boat, and will serve the same duty in the future as I refit one myself.

[ebb]

KEVLAR!!!
Ok, but you know how my brain works:
First of all if you hit that qnarly tree (I've actually SEEN that tree!) it's "unlikely" you'll get holed. The hull will crack, if bad will get stove in, but hold together.

If that is correct, then applying rubber and fabric is a better way. With the kevlar, the mechanical bond might not hold. Of course I don't believe this, but it is possible that the kevlar is so strong that it could be pushed off as a unit, as a skin, and let the water in. While a rubber skin would be more likely to expand and keep the hole covered.

Wonder if such a product exists off the shelf. I did search for awhile for rubber tank coatings (to create builtin watertanks) without success, but was looking for potable stuff.

What you think about the rubber alternative? (like hypolon) - probably exists out there already. Rubber tanks in the market for years now.

[CapnK]

Hey - if we are gonna go for it, let's go for it! A 3" layer of closed cell foam, bonded to the hull with 5200, and *then* encapsulated with a rubber skin. Object hits hull, pokes through hull, pushes foam out, lessening impact, rubber keeps any water which comes in contained, and rebounds, pushing foam back towards impact point. Unsinkable boat!

LOL, In all seriousness, I did think about using a rubber mat like you proposed. Perhaps thick enough, it might work. Here's a question which begs asking at this point - What do they put in the tanks of oil tankers? Or in airplanes, to make their tanks self-sealing? I don't know. I bet it costs a gazillion dollars, and only billy gates or a similar largish corporation can afford it.

[ebb]

THIN enough it might work. I'm an airobol lagging adhesive graduate. It was a pre-urethane Borden product (made out of milk?) that was a very thin waterbourne rubber that you built up thickness on plywood decks with canvas or a polypropylene open weave fabric called Yellow Jacket. It worked because it moved with the plywood where something thicker would have pulled away.

I just assume that any rubber stop would go on with some similar fiber in it, but it wouldn't be thick. But very flexible. These days there probably is a highly crosslinked coating from NASA. requiring 3 guys in Tyvec suits to apply it. And no cloth matrix. An advanced permanently flexible bubble gum. Hell, rather open a can.

We have maybe a philosophical difference on this subject. On a retrofit I feel adding superior strength is costly in weight and money. ( Have done this in 338 with added matt at the waterline forward with a beefed up stem and more recent with a heavily reinforced 'belly tank' under the sole - and a beefed up bilge under the cocpit)

I think a technical elegance is a better solution, tho it may not exist or reached the mass market. A thin very flexible adhesive membrane that would not punture readily is what I would like to see. The 'shards' of a masive puncture wound in the hull would not leak because of the stretchy membrane. Something smooth, in color choices, no VOC rubber that could be cleaned with a sponge. It would be painted on the hull inside everywhere below the waterline, wherever you thought protection needed - easy to repair and recoatable without abrasion.

What survives a storm? The stiff old oak or the bendy sapling?

A mat is a mat, something to pull away. Not looking for strength. Looking for tough bubble when you run into trouble. If somebody else chirps in here, they may point out that the Ariel hull is quite thick and strong. I think it depends where your boat is with its number. 338 might require the rubber treatment , as I found a thinner hull than 'advertised'.

Has anybody documented serious trauma on any Ariel or Commander and what it looks like?

What does a 6 to 12 knot run in with a pointy object produce?

Etap is a belgian 'unsinksble' hull within a hull sailboat with injected urethane foam between. Takes up a lot of interior space in a small boat. And there are issues with water getting in, foam collapsing, difficult repair - and it would be an extremely expensive hull made with the better foams like pvc and epoxy. Not applicable here.

[ebb]

C'pete's
option 2. Assume you have the extra gas aboard on your way to Bimini. You'ld have it in a 5 gal lashed in the cocpit. Your 6 or 8 horse two cycle 45 pounder would be in the lazarette because that's the best place for it. That means the well hole would be well plugged when well offshore.

338 came with a fiberglassed cube of foam the size of the whole hole as a plug: rediculous! A less massive lid that takes into account the slope of the boat yet with a flat top should be made. First, it'll be easier to store when out of the hole. Second, it'll provide a place for cocpit water to go quick, rather then slosh around on the deck under the ob. Third, a one way drain valve could be put in the lid to let the water out.

Off shore A/C's must have certain upgrades, IMCO. One of them is larger cocpit drains. Especially in the Commander because of their larger volume. But ditto the Ariel. Unless you are young and prone to taking chances. An airboat in a valise could be carried in the cocpit displacing volume, along with the gas can(s). Anyway