For the OP, personally I would be more interested in increasing water clearance to minimize wave slam on the underside of the boat. And I would also personally want to minimize total height to reduce aero drag. And there is an obvious trade
off and sweet spot between those two objectives.
As to pooping. I can make three comments.
#1 There is a particular operator error that is much more likely to cause it. I personally have made that error (and hopefully learned from it). We were in big waves and the wind
was building and we wanted to switch down from the #3 to the storm jib
. Our plan was to roll up the jib
and hoist the storm jib
. There was enough wind
to keep the boat steering
under bare poles as we were doing that. BUT when we rolled up the jib
the boat decelerated, just as a big breaking wave rolled up the stern, and right over the cockpit. If we had kept up speed that wave would not have broken over us, but with the sudden deceleration it did. Hit the cockpit pretty hard. What we should have done is hoist the storm jib first and then roll up the jib, but at the time it did not seem sensible to be adding sail area. (note: this was on a 55' custom M&M cat)
#2 There are just conditions when almost any boat of almost any design with almost any skipper
can get pooped. These sort of conditions are quite rare. But they do happen. Take a look at video of the 1998 sydney
to hobart storm if you want to see what it looks like. I personally would not have been real happy to be out in that weather
with a big light weight glass sliding door . . . but there are also a lot of other things that would have made me uncomfortable in that storm. Big serious breaking wave weather is just really really harsh and can break a lot of stuff that normally is just fine. When picking and outfitting a boat you just have to ask what sort of conditions are you going to prepare for.
I will note again those sorts of conditions are rare - and often a cruiser can sit them out in a nice safe harbor - but sometimes even the tropical cruiser does get hit by them when doing long passages (see queens birthday storm for example)
#3 Somewhat related to #1, but a broader point - operator experience and skill can mitigate ALOT of boat/design vulnerabilities. And operator inexperience can dramatically increase risk. And the more finely tuned the vessel the more these things are true. In sydney
to hobart sort of conditions there are three factors:
(a) there is just a certain amount of luck involved. If you get hit by that certain wave in that certain wave, it is going to destroy you almost no matter your skill and almost no matter your vessel design (we are talking recreational sail boats here).
(b) there are certain design elements that increase risk. I would say that the single
biggest is a lack of tracking in big waves, and (to make a generalization) multihulls tend to track/steer better than monos (which when heeled on the face of a wave often change their steering
balance and want to drive around). But I have to comment that down the 'added risk' list a ways are big pieces of glass - both from wave pressure but also from gear
strikes (see rainmaker). Most commercial
classification rules have long sections about size and engineering of big glass pieces. These can in fact be made really really strong (Dashew does) but that tends to be really really heavy and it is not often done of multihulls.
(c) Operator skill and experience can mitigate ALOT of risk. And operator inexperience can increase risk dramatically. And this factor (generally) increases the more highly strung the vessel. Highly experienced and skilled guys might not have flipped that Chris White 46 (?)
Boats are trade-offs. If you build the 'any seas, any seasons, any storm' boat then you will have made a lot of design decisions that will make the boat a bit less attractive in typical conditions. So, it is a tricky dance to make the right trade-offs for you. And that is one reason this is so hard for inexperienced people because (whether they know it or not) they just don't know yet what are the right trade-offs for them.