Thanks for the kind words. Before commenting on the stability matter, I add two points about objectivity:
isn't a purely objective process. As has been stated earlier in this thread, you (one) tend to choose your boat
then try and justify it after.
2. Aesthetics does play a big part. i couldn't bring myself to buy an ugly boat, no matter how well it met my technical criteria.
So, onto the capsize
v sink issue. i don't know how many monos have survived a full 180 roll, but there are many. Some monos sink after a capsize/rollover, others do not, it depends not only on the design but also the environment
and the way the boat has been operated ( e.g. if the seacocks are open when the boat is inverted, air can escape and the boat is more likely to sink). i think we ned to look further than the capsize
likelihood. Risk is about both likelihood and consequence, so the debate should extend to the suitability of the boat for survival once the catastrophe has occurred. Clearly some monohulls will sink, so they are not a suitable platform for survival, but what about those that remain afloat? They have to be fairly stable, yet not be awash with waves. These are two conflicting requirements in terms of hydrostatics, requiring careful design to obtain a satisfactory compromise. If a mono is fairly stable once it pops upright, and isn't awash, then it is a suitable platform. If it is awash, then it is dangerous. Many people criticised the crews who abandoned their boats in the 1979 Fastnet race
because their boats were subsequently found afloat, thus "proving" they had made the wrong decision. What got lost
in the noise
was the clarifying statement from some of those crew, that it was too dangerous to stay on board the awash boat - they were getting seriously injured from being thrown around.
If the mono does not right itself, it can still be a survival platform, but it is less than wonderful (e.g. the Tony Bullimore Southern Ocean episode c 1996)
So the monohull
can be a suitable platform for survival, but not all that often.
Multihulls rarely sink after capsize (but it has happened), and there are things you can do to make them habitable when inverted. however, they are purely a survival platform where you sit and wait rescue
, whereas a righted mono has a modest chance of setting a jury rig and getting to a harbour of refuge (e.g. Tzu Hang)
so the multi is usually a better survival platform than the mono, but cannot get itself to safety
. It is also (arguably) a bit more likely to capsize and a lot more likely to stay capsized.
When you put all these factors together, the question " which is better, mono or multi?" becomes rather meaningless, as it depends so much on the boat, the crew, and the environment
. And that's why there are both monos and multis used for sailing the oceans successfully. Unless of course all the above is a smokescreen put up by naval architects in order to keep themselves employed :-)
Kim Klaka MRINA