How Heavy? How Light?

If the building materials for a boat or anything else are too light (even zero or negative), you can always make it heavier by various methods, but the opposite is not true, you cannot reduce it to zero if it is too heavy. Lightness is relentlessly pursued because it gives degrees of freedom for design which you can't have with heavy...

That's the way I see it anyway.

Porta

 

There is no minimum weight for seaworthiness, there are only additional failure modes to consider.

The multihull reduces weight and replaces ballast with form stability. That added volume and area has to be capable of surviving surface conditions, notably wind and waves. A bigger compensation is required to replace the heeling reaction monohulls use to react to wind gusts. The great challenge of offshore race is that they draw power from such a wildly variable source. And the surface can be deadly as well. Interference can result in a 70ft breaking wave anywhere.

The other reason there is no such thing as a minimum seaworthy weight is that you can always take on ballast water. Consider the life raft that all racers cary -it weighs less than the sailors it can protect.

I think what you are looking for is the relationship between area, volume, shape and force aerodynamics and hydrodynamics. Going back to the multihull, the large surface area exposes it to huge forces, more from waves than wind. I suspect if you abandoned one in the southern ocean it would be crushed within a year. The only reason these boats can occupy these waters is what I call dynamic safety -the ability to recognize and sail out of bad weather faster than it can develop, and in this sense today's crazy light boats are more seaworthy than typical boats of the past.

Sailors today are killed by schedules, not by weather conditions.

 

About as true a statement as it gets. When the Atlantic Ocean was first traveled and traded across frequently, the merchant vessels that worked these waters often found a 50% attrition rate. Yep, every other boat would be lost. Yeah, we've come a long way since, mostly because of better, often lighter, material implementation, though knowing where the hurricanes are, when your gold stuffed fleet is scheduled to return, is a handy feature too.

 

Thanks all. I appreciate it.

So, it sounds like, as always, the material dictates the design. Design would have to compensate for the lightness to remain seaworthy. The outcome would probably be something much different to say the current Banque Poplaire. And where form stability ends, ballast comes into the picture. Something like that?

It will be interesting to see what materials will be used and how light some of these boats actually get.

 

It's a concert, not a solo or duet. Boats are about 1/2 the weight of the last century turn, for similar size and accommodation.

 

And what lovely symphonies they are - sometimes.

 

Especially the stainless halyards banging the alloy, in a duet with the in mast furler's 15 knot howl, while trying to sleep a few hundred feet away.