Aphers Posted February 21, 2023 Report Share Posted February 21, 2023 Very strange winds today. I'd just finished sailing my Spindrift and had taken the mast off. The boat was tied up to the back of my yacht but being pulled around side to side in the gusts. One gust managed to get under the boat and flip her upside down. The board was down- maybe that contributed because she 'tripped' on it, instead of just sliding sideways? I jumped straight in and got the boat righted again very easily. Pleased about that. But I was a bit shocked at just how much water was inside. The bow section especially seemed very full, with the centreboard casing almost awash. No harm done, and a useful little exercise. But it's got me thinking about reducing the volume in the bow section. I don't really want to add lots of weight. Has anybody modified their nesting Spindrift to provide more buoyancy (and less room for water!) in the bow? Quote Link to comment Share on other sites More sharing options...
Captain Tim Posted February 22, 2023 Report Share Posted February 22, 2023 Aphers, You should revisit this thread Spindrift 10n- Adding forward flotation By Starboard March 19, 2021 in B & B Yachts Forum Looks like it is just what you are looking for. 1 Quote Link to comment Share on other sites More sharing options...
Aphers Posted February 25, 2023 Author Report Share Posted February 25, 2023 A little update on this. As a temporary measure I've lashed down two fenders as low and forward as possible in the bow. I used the mast step and eye nuts on the nesting bulkhead as strong points. Next I deliberately capsized the boat. It took a surprising amount of effort. I turned her through a complete circle when righting so she was as full as possible. This time the bow section had much less water in it. Instead of the centreboard casing being awash, there's around 5" of freeboard. So the fenders are a useful precaution. Now I need to think about a permanent solution. Side buoyancy as @Starboardbuilt looks very good indeed. I hope he reports back at some point on its effectiveness. Another thought I had was to make up a foam floor, encapsulated in glass. This could serve several purposes: it would add buoyancy low down, and it would provide a dry, strong, flat floor which is easier to stand on and less susceptible to damage from anchors, bicycles etc. I'm thinking of making it a removable unit so that water cannot get trapped, but it could also be permanently installed. Obviously it would need to be shaped to give access to the self bailer, mast step, etc. Would there any negative effects upon stability with buoyancy at floor level vs the sides? Neither option is exactly a small job so for now I'll stick with the fenders and enjoy the sailing 1 Quote Link to comment Share on other sites More sharing options...
Captain Tim Posted February 25, 2023 Report Share Posted February 25, 2023 Aphers, Maybe you could rig up a bladder like is used in an Optimist. If there was a way it could be filled when needed with a co2 cartridge like an inflatable life vest. Just thinking out loud. 1 Quote Link to comment Share on other sites More sharing options...
Aphers Posted February 25, 2023 Author Report Share Posted February 25, 2023 I've done another couple of capsize tests today, this time with the mast on. My mast has a sealed top so it has enough buoyancy to prevent inversion, and I was able to swim round and right her. I think for stability I might be best to go with lateral tanks. Seeing the free surface effect in action was... interesting. A raised floor might help reduce the amount of water taken on, but it's not going to make the boat any more stable once righted. Quote Link to comment Share on other sites More sharing options...
Designer Posted February 25, 2023 Report Share Posted February 25, 2023 Placing the flotation at the keel is the worst place to put it. It raises the CG of any water on board and it encourages what is called "free surface effect" which is all the water rushing to the lee side when the boat heels causing the boat to heel further and possibly capsize. It makes it harder to board a partially flooded boat without re capsizing. As has been stated, the standard Spindrift layout is the best. As you have a S11N that is not possible. What Starboard did is the best that you can do, which is pretty good . Look at the pictures of a standard Spindrift on it's side, you will see that the water does not enter the boat. When righted you should only get the water that is scooped between side seating and the side which should only be a couple of gallons. In the real world that might not be the case as the dagger board is forward of the heeled CB causing the boat to trim down by the bow as you lean on the dagger board and taking a fair amount of water on board. Having capsized Spindrifts a lot I found that they are small enough that I could could put an aft twist on the board before pushing down and eliminate the problem. With the layout that Starboard has, you should be able to right the boat with a fairly dry bow section but a quarter to half full aft section which puts you into a lot better situation than you are in now. you should have a tied in bailer ( modified gallon chlorox bottle. Probably the best thing in the world for kids is having a Spindrift. I would give them plenty of practice capsizing and self rescue. It is easy to right with the boat on it's side but much more difficult if inverted. The will invert without mast head flotation making it difficult to right. It is often too shallow to completely invert, risking mast damage or at least a very mud stained sail. I never felt the need for mast flotation because I got onto the job of righting the boat. I have seen plenty of people dither taking too long and getting inverted. I see that Aphers responded while I was writing this so some of this is duplication. 1 Quote Link to comment Share on other sites More sharing options...
Aphers Posted February 25, 2023 Author Report Share Posted February 25, 2023 Thanks as always. I'd already pretty much come to the conclusion that floor buoyancy wasn't going to work. Just had to see how the boat behaved when partially swamped. Next time I'll try to keep my weight aft if possible during recovery. Proper built in lateral tanks look like a great idea, obviously it's adding a little weight. Maybe a job for the end of the season. It's hard to make modifications like that when I need to use the dinghy every day. As a temporary measure I'm going to install a couple of lashing points on the forward bulkhead, low down in the corner at the chine, then use these plus the eye bolts at the nesting bulkhead to secure buoyancy bags or fenders. I might do something similar in the stern section too, with the aim of getting the boat to float a little higher when capsized. Obviously those would have to be removed for nesting. Quote Link to comment Share on other sites More sharing options...
Reacher Posted February 25, 2023 Report Share Posted February 25, 2023 Aphers, floatation placed high in the boat, snugged up under the rail or side deck is good. When the boat is capsizing or laying in its side, what was the high point while sailing becomes the low point at capsize. 1 Quote Link to comment Share on other sites More sharing options...
Captain Tim Posted February 26, 2023 Report Share Posted February 26, 2023 Designer said, "Probably the best thing in the world for kids is having a Spindrift". When I told my wife this, she said, "so does this mean you're never going to grow up?" 1 3 Quote Link to comment Share on other sites More sharing options...
Don Silsbe Posted March 20, 2023 Report Share Posted March 20, 2023 @Aphers— I’ve already given this detail, so I’ll keep it brief. Forward floatation worked wonders in my nesting pram. The higher float encourages turtling, though. I made a mini masthead float. (Not shown.) 1 Quote Link to comment Share on other sites More sharing options...
Aphers Posted March 21, 2023 Author Report Share Posted March 21, 2023 I did a deliberate capsize the other day, and righted the boat without using the board at all. I was really surprised how easy it was and it meant I could keep my weight right aft where there is more buoyancy. As a result the bow section scooped up a lot less water than on the previous capsizes. I'm glad that the accidental capsize happened- I'm much more confident about the boat's behaviour and stability now. In fact I've started using it as a way of cleaning the boat when it gets sandy after a trip to the beach. And my 7yr old lives playing underneath the upturned hull 1 Quote Link to comment Share on other sites More sharing options...
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