Bare in mind that I haven't done long distance passage make or cruising, but have read lots and done lots and lots of coastal cruising and hanging out in great coves and bays in out of the way places. With that preamble, my thoughts are as follows:
1. How long should a passage making catamaran be, is often very dependent on personal preference and perspective. I've read about folks using 32 footers (or even less) for cruising and passage making, though many feel bigger and longer is better.
2. How tall should the mast be for a passage making and cruising cat is also (likely) dependent on personal preference and perspective. Again, many seem to feel bigger and taller is better.
Though taller allows more sail area and more speed in light wind conditions, taller isn't useful in raucous conditions. In such conditions we all reduce sail area often by shortening the main.
To reduce loft, trimarans often use a shorter ketch rigged set up and shorter booms, rather than a taller sloop rigged one, with a long boom.
I'm not sure there is a boat length to mast height standard.
The beauty of a catamaran is in heeling stability, while sailing and deck area, interior space/capasity and accommodations while moored, anchored or at a dock.
I believe you could put lots of catamaran boat length, under a 45 foot sloop rigged or ketch rigged mast set up.
Last edited by tomthouse; 06/26/12 11:39 AM.