Masthead Bouyancy

Oh, OK then. Thank you Frank (for thinking of me).

Think for classes like the 49er, 29er etc, designing the boat to invert is a very safe design feature. The 49er especially has a lot of windage when on its side, probably higher than quite a few dinghy classes, so if you go over and the boat stays on its side, unless you are in constant contact with the boat, it will sail away from you at a considerable rate when the wind is up. Not so much a problem on a pond but a serious issue on a coastal location. Tidal drift can also be a problem, although a boat will tend to drift with the tide relative to your own body's drift, therefore, wind created drift poses the most danger. Isn't so much of an issue with the Tasar, although they are beamy and quite susceptible to wind drift, but as Jim says, doesn't really matter which boat you sail in certain wind conditions, they will all drift on their side. The difference is that if a crew memeber becomes detached from a capsized boat, it's fairly easy to right something like a Tasar single  handed and sail after them to pick them up. Trying that manouvere in a 49er when it has been windy enough to force you over may be beyond the limits of most sailors, hence why minimalising the likelihood of crew dettachment is very important.

Originally posted by 49erGBR735HSC More often than not, people who are learning to sail or relatively inexperienced aren't "quick" enough

I'd agree with that, it's usually the weight of the people on the boat that make the boat invert. The resistance of the sail going through the water means that you've probably got at least 30 seconds on pretty much any boat if nobody is hanging onto it before it goes beyond lying on its side.
Having got back into a Laser recently after sailing boats a lot less wobbly on the run, I've had a couple of fast windward capsizes (the sort which make people look round because of the "Bang" as the mast hits the water!). Neither time did the boat turtle, probably because I  went straight into the water, underneath the gunwhale (under the water) and onto the centreboard rather than attempting a "dry" capsize.
However, for unsupervised novices such as people hiring club boats, particularly on a shallow lake, a large inflatable item tied to the top of the mast is a good idea as otherwise the rescue boats spend all day towing masts out of the mud. It doesn't do the sails much good either!

Originally posted by 49erGBR735HSC The majority of masthead floatation devices which I've seen on boats such as the Topper range (Omega) etc, Laser Stratos don't work. Our local sailing school puts inflatable bouys on the top of their Omega masts as they know that the masthead bouyancy devices designed into the boat don't work. The Stratos float was just a hassle whilst raising the sails and didn't really help keep the mast floating.

 

The Topper masthead floats do work in that they slow the inversion. If one of you can get on the board quickly then they do actually help keep the boat balanced and it can be easily righted by a fairly light person. If you go in for a windward capsize (as in numpty helm losing his grip of the sheet) then it's gonna turtle.

Originally posted by JimC The other thing you need to consider is that if you are sailing on open water then masthead floats dramatically increase the risk of the crew losing contact with the boat after a capsize, since in a reasonable breeze the boat will blow downwind faster than someone can swim. This has happened to me, and since the nasty fifteen minutes I spent in the Solent watching a boat drift half a mile or more away from me I will never again have a boat that doesn't invert within reasonable swimming distance. (And many thanks to Gosport Inshore rescue)

You have mentioned this before on other threads, Jim and I'm curious to know what boat it was that got away from you. I had a similar experience when I first sailed a Vortex on Belfst Lough - and that was without mast floatation! I didn't actually need rescuing but many thanks to al the curtain-twitchers of Ballyholme for calling out the RLNI anyway!

For boats that float very high in the water when on their side I can see your reasoning. A GP doesn't fall into that category, I think so they should be all right.