If I were to design something from scratch, I would put in some things I've never heard of anyone trying. Here's a starter list. Please feel free to add or comment upon it.
1) No underwater through hulls. Yes, it's radical, but I would want engines that could be raised and lowered from above the waterline.
Electric, gasoline outboards, don't really care, but they go up and down above the waterline. Any
water needing to come into the
boat for dishes, or
cooling or heads would go up through a blended in conduit on the inside of the hulls which extends below the
water and then penetrate through the
hull well above the waterline. Actually one foot above where the waterline would be should the largest watertight compartment be breached. The same would be true for
depth and speed inducers, they would be included in small tubes inside the inner
hull which go below the waterline but the
wiring enters far above the waterline. This doesn't have to be ugly. The hull can be smooth and continuous with the conduits hidden inside the
boat instead of outside, just as long at the through hull location is way above the waterline. Think of the headaches this eliminates. Where's that leak? Unless you breach the hull, there is no leak.
2) Watertight compartments. Every
cabin you would need to step and through a bulkhead which is high enough to prevent water moving from that compartment to another compartment should that compartment breach. OK, so you step up, big deal. I'd rather have something slightly awkward to enter and know it's completely watertight compartment. I like to be reminded that I'm on a boat rather than trying to live the illusion that I'm in a condomium.
3) no metal below the waterline. Actually if there are retractible engines, then there really is no need for metal below the waterline. Let other
boats worry about
diving to check their zincs and saildrives.
4) Replaceable striker plate rubrails on the leading edges of the boat. Think of it. they put rubrails mainly to protect against scratches, but not collisions. How much sense does that make? I want normal rub rails too, but make them where they are needed, not just wanted. And make them robust,
steel over hard vinyl for shock absorbing type things. False foam bows are nice, but they can't be as strong as
steel rub rail and certainly not as easy to
repair.
5) Have a dedicated retractible
lightning rod extending straight down from the
mast. Make sure it's a piece of metal that goes up and straight down from the tip of the
mast through the center of the bridgedeck hull to the water. Why don't
multihull manufacturers design for
lightning strikes? Monohulls do.
6) Redundant field replaceable independent interchangeable units for things like nav lights,
deck lights,
instruments. Think tacktick
instruments evolved to cover more things. Your nav lights with their own
solar panels, light
sensor and a wireless on and off controls. You loose a nav light, oh well, you grab another one, switch it to green, walk over to the bow and replace the broken one with a light that could be the white all around light, the red and green, or a
deck light. All using the same housing but a moveable
solar panel, different colored lenses and a movable plastic housing adapter that adjusts where and what angle it shines from. Also have ones that can be used inside, sitting on the rail ready to go. No wires going to anything. Loose the
battery bank? Your lights and instruments still
work. Oh, now you don't have to worry about wires coming back through leaky conduits. No wires going through the mast either (Tacktick instead).
7) of course all the usual (or what should be usual), accessible side
panels so you can see every space of the boat.
8)
Solar powered
panels built in, sufficient to
power everything in the boat. Use the deck space to have
solar panels, or better some sort of solar film. Built it in from the start rather than having to clumsily stick it on afterwards.
9) Hatches facing out but not up. Design it so you can get sufficient ventilation and
lighting from outward facing hatching and
ports in the hulls. Protect from rain every dead light through a lip. Prevent
leaks before they start. I've got several leaking hatches on our boat and well, I'm pissed. Maybe it's not rational, but maybe it can be done. I do like the idea though of a clean deck with nothing to leak and nothing to stub your toe on. Just seems a problem waiting to happen to put an opening window on a flat roof. Maybe permantly sealed deck prisms for light and opening hatches in the hulls. I think one of the most esthetically pleasing things is to look into the water between the hulls.
10) it's sort of stated elsewhere, but retractible engines. I want to be able to get the thing out of the water completely. I also want to be able to hoist it using the mainsheet out of the boat and dangle it like a
Christmas tree ornament for
repair at every possible angle.
That's it for the rant. Now I'll let the bigger winds blow.