Tri or Cat

[Sand crab]

Some of the really old tris supported the weight on all 3 hulls and you can see this really well when they are on the hard with all 3 hulls basically the same depth. These had too much wetted surface and other issues and were therefore pretty slow but still faster than most monos. They carried a load OK for a multi. They had the advantage of usable space in all 3 fat hulls but that design really hasn't been used in 20 years or more. Nowadays you need a tri above 56' to 60' before the amas can be used as interior space and then all of a sudden you have a really big boat inside.
Get Gregor Tarjans book Catamarans. It's at Barnes and Noble. It costs $40 and it's worth every penny. Chris White has a good book too. BOB
REFERENCE BOOK: “CATAMARANS, The Complete Guide for Cruising Sailors” - Aeroyacht

[Sand crab]

I said 20 years when i should have said 40 years. Here's one.
1970 Custom Built Williams Trimaran Pilothouse Ketch Sail Boat For Sale -
Only $39,000. What's not to love. This looks like a Piver or close copy. They were very innovative for their time. Good luck BOB

[James S]

Originally Posted by Sand crab

I said 20 years when i should have said 40 years. Here's one.
1970 Custom Built Williams Trimaran Pilothouse Ketch Sail Boat For Sale -
Only $39,000. What's not to love. This looks like a Piver or close copy. They were very innovative for their time. Good luck BOB

Looks like a lot of boat for the price.

[barnakiel]

Both!

Cat is practical though, if you are married.

b.

[DaveOnCudjoe]

It's important to remember that, be it cat or tri, the righting moment is greatest if the weight is kept along the port/stb centerline. Probably easier in a tri and though some of the classic designs included accomodations in the amas, it's no surprise that it no longer appears in modern designs. Perhaps the best argument for sealed amas(floats) in a tri is the bouancy remaining if the main hull is flooded. I remember a failure in the head supply line in my old Piver, resulted in about a foot and a half of water that was easily bailed after effecting repairs. Dave

[HapaPops]

I'm in the process of selling a late model trimaran (Contour 34) and hopefully replacing with a catamaran of similar size, age, etc:

Trimaran:
Quick
Nimble
Sails really well - big air and light
Goes upwind nicely
Traditional secure feeling in the cabin
Acres of free deck space
Max righting moment right when main hull lifts free - lots of warning before than happens (in modern designs)

Small cabin, small load capacity
Cockpit is similar to a monohull - low to the water - and unless it's a pilothouse - not very protected.
Outboard engine can cavitate when you really need it...

Catamaran
Most have fixed keels - definitely a sailing compromise - sail plan not as efficient (look at those high clew jibs)
Lots of air resistance (not always, some are designed with performance in mind
Great open space with enclosed bridge deck
Max righting moment when the weather hull lifts free - not necessarily much warning

Some manufacturers take advantage of the extra space and overload the boats - further detracting from performance - but guess what sells at the boat show?

Very protected cockpit in most cases - some with open walk through passages into the bridge deck cabin - older designs usually have smaller doors so they seem like more separate passages, and the person on watch is more exposed if not sailing under autopilot.

Cats cost more in general for the same length, tris closer to cost of monos, - but in terms of displacement (volume, not weight) all boats are similar. You get a lot more volume in 10 meters with a cat, than a tri or a mono.


Why am I switching? If it was just me- or I lived where it was warm - I wouldn't. But with 2 kids + spouse + extended family, we want a boat with shelter when going upwind. The decision happened this summer - as we buddy boated with an older Seawind 1000. Guess where we congregated for sundowners? When we did the upwind (20+ knot directly upwind) bash home (about 40 miles worth) what did my crew wear (full gear) and what did the cat sailors wear? Shorts, t's and flip flops.

While our boat was great on the downwind delivery - eating up the miles at an easy 10 knots - the bash home was cold and unpleasant. The Cats delivery was also unpleasant, but not cold….


Edit: my trimaran folds - and has a trailer. Those cats are hard to deliver quickly and inexpensively. Main option is on their own bottom.