Sink or Swim??

Discussion in 'Multihulls' started by Richard Woods, May 5, 2009.

  1. rayaldridge
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    rayaldridge Senior Member

    I'm not sure that's exactly how they would put it, though that may accurately describe the position they take.
     
  2. BeauVrolyk
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    BeauVrolyk Sailor

    Richard, you're always welcome. We try to insure that we never leave anyone on shore, and so far everyone who's showed up (even some without proper gear) have been able to go sailing. There is still one old 1/4 tonner, "Fun" a Davidson, that races around here a bit.

    Oddly, I have lived in both Florida (Fort Pierce) and California (LA and San Francisco). I ended up in SF after living a lot of places, including New Zealand (Auckland and Bay of Islands), because I liked the combination of sailing in a breeze, mountains for skiing nearby, and a lot going on.

    I don't think I ever gave Hurricanes vs Earthquakes a thought. But, I do know a lot of people worry about those sorts of things, the things that almost never happen. It's like these posts in this thread, people spend a lot of energy talking about stuff that very very rarely happens. Both camps haul out the most dangerous or frightening thing that they can think of about the other kind of boat, even though the probability of being killed driving to the boat is vastly higher than the probability of getting killed aboard. People are really funny that way - they want to focus on the dramatic - no matter how improbable. If one were to really worry about disaster related injury or death then Tornados are the worst, as far as I can tell, so you should stay out of the mid-west. But, it's just not relevant. The best way to have a longer life is to loose weight and stay in shape. That's a lot more important than how many hulls you have on your boat.

    Finally, I decided decades ago that owning a boat and sailing around on it is fundamentally irrational, we do it for emotional reasons. Thus, when we try to have a "rational" discussion about boat types etc... it always degrades into a set of silly discussions, as we've seen in much of this thread. After all, how many on this thread have actually ever personally sailed over a 40 to 60 foot tall wave? Darn few, I'm guessing. Given that the choice of a boat is an emotional decision, then one should choose a boat that causes a positive emotional response and gives one pleasure. It is entirely a personal choice, and no amount of "debate" here or down at the sailing club bar will alter it. It's sort of like discussing blonds or brunettes. My brother, he likes blonds, I like brunettes. There's no "rational" discussion that will change that. I've tacked URL of a picture of the sort of boat that warms me up, doing what they love to do in a breeze on San Francisco Bay. Not for everyone, but if you love it, you love it!

    http://www.shutterfly.com/progal/slideshow.jsp?auto=0&aid=768a5498cf52df1c802f&idx=23

    All the best,

    Beau
     
  3. Bruce Woods
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    Bruce Woods Senior Member

    Richard, don't get me wrong, I have great respect for your accomplishments and your willingness to educate those new to multi-hulls. It certainly surprised me , the number of people taking this thread so seriously. Keep posting.

    On a slightly different tack I spotted a glass production version of one of your designs in Darwin (Australia). 20 odd feet, open wing, not sure what design. I understand it made its way out to New Guinea , from Europe on its own bottom before ending up in Darwin with new owners. Were merely transiting through, but don't see to many of your designs in this part of the world. Nice to see a moderately sized cat with so many safe ocean miles up. Well done on another good design.
     
  4. BeauVrolyk
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    BeauVrolyk Sailor

    A Nice Looking Cat

    Have a look at this: http://www.lebreton-yachts.com/gallery-and-video.php

    There are some very appealing features to this boat, although you've got to like bouncing on a tramp, even the aft deck is tramp. This looks like the sort of Cat I'd want for doing the South Pacific again, if I ever do it again. Great warm weather boat.

    BV
     
  5. Manie B
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    Manie B Senior Member

    Me too





    now my turn :D


    beautifull pictures of a MONO that is unsinkable going fast enough :D


    i looooove this thread :idea:
     

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  6. Manie B
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    Manie B Senior Member

  7. rayaldridge
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    rayaldridge Senior Member

    Judging by this thread, it seems apparent that it hasn't. And this is the section of the forum devoted to multihulls.

    I wonder how you'd be received if you went over to the monohull design section and asked why folks there were content to risk sinking?
     
  8. BeauVrolyk
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    BeauVrolyk Sailor

    Manie,

    I talked to these guys via email and they use an injected foam that is sort of like (not exactly like) the foam in a Boston Whaler, I think it's on their web site. The difficulty is that these foams have a pretty bad reputation for soaking up water and breaking down. While these boats are purported to be built with a much better foam than the Whaler, the other difficulty is to insure that you've actually "filled up" the area of the boat being dedicated to flotation. There are usually air pockets left behind.

    I think there is a better way to do this, which I think I posted quite early in this thread. There are lots of reasons for extra tankage in a boat, and one of them is to provide movable ballast. Also, and empty tank of air is a lot lighter than the same volume filled with foam; it does require construction quality that insure it is air tight. If a skipper can be trusted to understand the buoyancy purpose of the tankage, then one can simply design a boat that has two times the flotation required in tankage, spread it to either side of the boat by building a double hull, and only fill it half full. Then, when you want extra stability you move all the fuel/water/vodka (don't laugh my old boat had a 25 gallon vodka tank, even a deck plate that said "Vodka") to the windward side. BTW - this technique would work perfectly on a multi-hull as well as a mono-hull.

    On the old Saga we had the ability to get her heeled over around 5 degrees while sitting at the dock. I did a rough calculation and that was about equal to having 28 200 pound guys on the weather rail - a big deal. Best thing was you didn't have to feed them or buy them beer. I really don't understand why building a double hull boat with the gap used for tankage and ballast isn't more popular with cruisers. It's a much better use of the space than foam dedicated to flotation. (CE regulation probably has a lot to do with it.) Also, if you're willing to take the risk and need the tankage, you can always fill the boat all the way up. We would do that with the water tanks when at anchor in the tropics and collecting rain water - lots of lovely showers. Finally, the tanks were divided into eight sub-tanks with a manifold and as a result I could trim the boat fore and aft so that she sat on her waterline. I'm certain you've seen numerous cruising boats that are badly down by the stern because the storage spaces tend to be larger back aft and cruisers fill 'em up with heavy stuff. Aboard Saga we would keep a bit of spare fuel up forward to keep her sitting on her waterline and sailing right.

    Best,

    Beau
     
  9. mydauphin
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    mydauphin Senior Member

    As far I am concern, every area under floor should be a tank. In other words a double hull. Small areas can be left open for a bilge pump. As stated above such a vessel even if tanks are full of fuel probably won't sink.
     
  10. TeddyDiver
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    TeddyDiver Gollywobbler

    For someone having dive gear onboard, making connections from scuba air tanks to water tankage gives the possibility to blow the tanks empty "sub style" fast and reliably in case of an emergency.. If the tanks just are sturdy enough :)
     
  11. BeauVrolyk
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    BeauVrolyk Sailor

    That's a darned good idea. I had a dive compressor aboard and it never occurred to me! I will remember that. The boat was steel, so she was plenty strong enough, just route a hose from the bottom of the tank up over the side (I'd be afeared (sic) to have it hard plumbed in), close off the vent, and open the valve on the air tank! Thanks. That should work much better than a pump .

    B
     
  12. BeauVrolyk
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    BeauVrolyk Sailor

    The battle I've always had with folks - and BTW I completely agree with you - is that they think the tanks take too much storage space away. I keep responding with "Take less stuff, your boat's sinking." but, they want all that junk with 'em.
     
  13. mydauphin
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    mydauphin Senior Member

    Beau, If you check on my posts my pet peeves are people stuffing their boats beyond their design limits, putting the largest engines that fit and then asking why boat doesn't perform properly. An pound off the ship, is worth two of water.

    Air idea is cute, but that means you have to an open seacock to blow water out. The idea of double bottom is that if there is a leak it most likely into or out of tank, therefore sinking is limited. If tank is leaking into inside compartment then obviously you should alarms to warm you, but it should be a small leak. Flooding cause by shaft falling away or broken exhaust can be limited to a close engine compartment. Yes, you might lose 30% of your boat but it should not sink right away.

    The bigger problem is rain water... People forget about it and it can accumulate. I lost a boat to rain after bilge ran down battery. It rained straight for two weeks... Really.
     
  14. TeddyDiver
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    TeddyDiver Gollywobbler

    As a safety precaution a regulator or a safety valve to make sure that the appropriate pressure won't be exceeded.. Smth like 0.3bar is propably enough thou depends of the tank and outlet..
    I'm building the tanks inside a long keel in 6 separate sections making totally about 800l. Each one to be used independently, and when emtied, flooded with sea water instead. So I need to empty sea water before filling fresh. I'm using the same plumming for filling and blowing (overboard) so there's no need for seacocks.
    With the a seacock directly there would be less counterpressure thou.
     

  15. BeauVrolyk
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    BeauVrolyk Sailor

    Safety pressure release is a REALLY good idea!

    So.... you're building tanks that will always be full? You need the ballast? On water ballast boats I always run with them empty down wind.

    You may find that it takes a number of cycles of filling and then emptying if you want all the salt out of the freshwater for drinking. For showers etc... no problem, but I was amazed at how little salt my kids could detect. Try it on a bottle, you may be surprised.

    What sort of boat is it??

    B
     
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