"DSK" wrote in message

I'd say that either displacement or cubic capacity equals comfort.

As a rule, yes, but a hull of a given volume can reach a point beyond which
increasing displacement has a negative effect on comfort, not to mention
safety. An example of this was a Norsea 27 in which a middle age man set
out to circumnavigate some years ago. The boat has an unladen disp/length
ratio of nearly 450, and with stores, extra fuel, water, equipment, etc. the
boat was simply too heavy and performed horribly in beam seas, which rolled
her over several times before he turned tail and headed home. Displacement
seems to offset cubic capacity somewhat, making really voluminous but light
boats uncomfortable and making voluminous and heavy boats more comfortable.

Max