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V Twin

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Owenfackrell View Drop Down
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    Posted: 25 Apr 12 at 9:12am
The sealed mast on my dart will not stop inversion but it will help recover from it as once you get it started it wants to get to the surface. Ok a cat is different to the V twin but a sealed mast can only help. Mythbusters used ping pong balls to lift a sunken boat from around the 7-8m mark and they worked really well.
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Post Options Post Options   Quote bferry Quote  Post ReplyReply Direct Link To This Post Posted: 25 Apr 12 at 8:59am

How about using a wind surfing/kayak type lasoo tied to your foot or would this restrict moving about the boat/water? It seems to me that you want to ensure that the helm and boat don't part company in the event of a capsize.

Bernard
Vareo 249
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ASok View Drop Down
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Post Options Post Options   Quote ASok Quote  Post ReplyReply Direct Link To This Post Posted: 25 Apr 12 at 8:42am
Sealing a mast has to be the way forward. I don't care what the calculations say about weight of water in water etc. but when you try and right a boat that has a mast full of water its near on impossible to get from near 90degrees to upright.

Previous points are very valid regarding the need for this boat to invert if it goes over. The sheer size of the thing and its design as a light weight - its going to drift off down wind quicker than you'd every be able to swim.
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Post Options Post Options   Quote bferry Quote  Post ReplyReply Direct Link To This Post Posted: 25 Apr 12 at 8:30am

Good point! I never considered inspecting them since they are still packed in the mast.  I'll have to take the mast down and inspect their condition.   The Vareo mast has a holein the bottom which fits into the mast pot.  The main problem encountered by Vareo sailers is that the water in the mast pot rushes to the top of the mast in a capsise thus accelerating inversion.  Some owners use the base of a bottle to cup the mast base and prevent this from occuring. I had tried this but found that removing the mast through the bridge could cuase damage due to the increased diameter of the mast (when the bottle base gets stuck fast to the base of the mast and has to be removed as a whole)

 
In hindsight, the boat used to stay on its side rather than invert when I originally filled the mast with the balls.  Maybe the inversions are a result of crushed balls (excuse the pun).  I was considering using swimming noodles like these which seem more buoyant and less likely to crush although they tend to absorb water over time.


Edited by bferry - 25 Apr 12 at 8:35am
Bernard
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Graham T View Drop Down
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Post Options Post Options   Quote Graham T Quote  Post ReplyReply Direct Link To This Post Posted: 25 Apr 12 at 8:16am
Bernard - if you have inverted a few times with the ping pong balls in your mast I would be interested in how well they have survived - I would have thought that being 15 feet underwater water they would be crushed, unless the mast sealing prevents water ingress at all. Is it possible to get a look at them or is the mast too well sealed?
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Post Options Post Options   Quote bferry Quote  Post ReplyReply Direct Link To This Post Posted: 25 Apr 12 at 8:09am
Originally posted by rogue

Yep, although not sure how he'd launch it off the beach!
The gap under the hull seems made to measure for retracting a lifting bulb keel, however having a keel would be a major departure from the design concept of the boat.  I've got my vareo mast sealed at the top and filled with ping pong balls and it does help slow an inversion, but not prevent it, especially in a blow with the windage and waves pushing on the hull. 
Bernard
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Post Options Post Options   Quote ham4sand Quote  Post ReplyReply Direct Link To This Post Posted: 24 Apr 12 at 10:47pm
zippy, the fact that my crew couldnt right the boat before the mast was sealed and now can easily means that it does kinda make a difference. letting off the kicker can help too, and obviously uncleating the jib
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Post Options Post Options   Quote Do Different Quote  Post ReplyReply Direct Link To This Post Posted: 24 Apr 12 at 10:44pm
I'm not saying a sealed mast or a little mast head flotation is a bad thing, but ........................

I am with Oldarn & RS400 in thinking the biggest problem is in the distribution of the buoyancy. Those large capacity side tanks / hulls are the killers, they make it float high and drive the mast down and once inverted make it impossible for a solo to sink a side and rotate it back to horizontal.  

I think less would be better than more: slim down the bean ends and forget the inflatable racks.
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Post Options Post Options   Quote RS400atC Quote  Post ReplyReply Direct Link To This Post Posted: 24 Apr 12 at 8:49pm
If the top of the mast is open, it drains as the heel is higher than the waterline.
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Post Options Post Options   Quote zippyRN Quote  Post ReplyReply Direct Link To This Post Posted: 24 Apr 12 at 8:48pm
The  weight of the water filled mast is a red herring while inverted as it;s effectively zero'extra' weight while it;s under the surface  , what  makes it hard to right to 90ish degrees is the just the area of the sails  and the tonnes of water you have to move to get the sail through the water to the surface ( consider  the size of the foils vs the size of the rig ... ) once you are at 90ish degrees a mast full of water does not help but once you've got that little bit of effort in the mast should drain relatively quickly ... 

hull buoyancy and it;s distribution is important as arguably there are boats with insufficent buoyancy ( i.e. those that swamp and are barely able to keep the plate case or transom above the surface ), sufficient buoyancy but in the wrong places ( big side tanks that raise the hull too far out of the water for easy righting but  the boat  comes up with some water on board which can be cleared via transom flaps / self bailers  / self draining  ) and some with excess buoyancy ( even worse version of the problems  with  buoyancy in the wrong place)  these all post problems to righting and recovery from capsize 


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