Of course, the "perfect"
boat is a subjective thing and depends much on intended use, but here are some of my thoughts:
I've run a lot of different makes and models of cats as a
charter captain/delivery skipper/instructor/cruiser and developed some definite opinions from this experience.
First, most modern cats share several common design flaws (IMHO).
1.
Helm placement. Almost all product cats have helms in less than ideal places (like the
cockpit bulkhead). Those that I think have it right: Chris White, Gun Boat,
Maine Cat,
Wharram (see new larger models like the
Pahi and Islander). For the worst ever
helm placement see the Nautitec 44.
2. Bridge
deck clearance. Most South
African cats have relatively low bridge
deck clearance or at least taper to low clearance aft -- more is better.
3. Deck House. Huge deck house structures to maximize accommodation spaces create more windage, reduce visibility, and add weight. I prefer more minimal deck house structures, like Chris Whites, or none like
Wharram designs (see
Pahi &
Islander models)
4. Sail Plan. The typical huge main sail driven
sloop rig is not the ideal cruising sail plan. That big main can become a liability for cruising and takes more muscle to handle. More, smaller
sails is a better cruising sail plan (true of mono or cat). A
cutter rig or schooner (like some Wharram's) is a more practical cruising/offshore rig.
5.
Engine Placement. The stern of the boat is the wrong place to put more weight (better than the bow I suppose, but midships is better). Stuffing lots of space in the stern also necessitates wider profile of the stern hull sections which reduces performance -- a narrow smooth profile -- both bow and stern is better. See Wharram and Gunboat for better
engine placement ideas.
6. Exposed
Rudder & Drive. Try running over a
fishing net in almost any production cat at night -- it's not pretty. Better to have an under body design that will slide right over things that go bump in night...more like a traditional full keeled mono. Again, see Wharram (no I don't like ALL of his design ideas, but he does have some very good ones).
A few other things to consider.
Heads. Mid-ship heads (like on some FP's), accessible by all guests, is a good practical consideration. I think that boats with in-suite heads in every
cabin are ridiculous -- who needs that many heads? And of course you have to maintain them all.
Sail Drives. I've had good luck with my
Volvo sail drives, but they do increase
maintenance concerns and costs. If you ever have to do major
repairs to one then you will need someone with
training, experience, and the long list of specialized tools and
parts to fix them. The
parts are wildly expensive -- I had to replace a damaged prop shaft on one -- this shaft is less than 1' in length and was $450 from Volvo! My preference is a good old simple shaft
draft which can be repaired easily anywhere in the world you can find basic machine shop services and materials. Even better: some Wharram designs use lifting shafts which not only eliminate the fouling issue when under sail, but also eliminate drive related through hulls -- I have not sailed with these, but sure do like the idea.
Engine Access. Most cats have quite good engine access -- especially if compared to older monohulls, but some better than others: Some FP's for example have a bulkhead just inches from the front of the engine which makes even simple routine
work a huge pain. Engine placement where you don't have to remove a bunk, and all the crap inevitably stacked up on it, is much more convenient.
Visibility from Helm. Stand at the helm station. Can you see all 4 corners of the boat -- not on most production cats. Twin helms can help with this issue, but many production cats designed with twin helms in mind don't have full helm control (steering and engine controls) actually installed at both helms (see this on Privileges a lot).
Deck
Security. All that deck space sure is nice for fair
weather sailing, but think about how you will move about the deck in heavy
weather. Where are hand holds/padeyes built in and where will you need to add them.
Ventilation. A
monohull with a couple of big deck hatches is easy to turn into one long
wind tunnel. Some cats, especially many FP's, are more challenging to ventilate well (the french apparently don't believe in ventilation...even newer FP designs have minimal ventilation in some cabins...especially aft cabins...those silly little round hatches sure are stylish though!).
....and the list goes on...