Catamaran on the boat lift

[leont]

What are the negatives of keeping a small sailing catamaran (36 ft) on the elevator boat lift? Hurricane straps can be added or it is safer in the water. Would it be bad for bottom paint, hull deformations, etc.?

[catsketcher]

Gday Leont

Firstly - who said 36ft is small? I have a 38ft cat and I find her quite ample. If she hears that 36ft is small then she may get a complex.

That said - I don't even know what an elevator is. What I do know is that cats should be lifted and supported properly. For some cats, it is good to support them on their keels, but you should be able to go inside and find some nice structural bulkheads, well tabbed to the hull interior laminate. If the bottom is glass or has foam with about 1200gm of glass on the outside at the keel, you should be fine with blocking under the bulkheads and softwood blocks where the hulls are blocked - carpet under the softwood is best.

If the laminate is less then I would use high density foam between the softwood and the hulls. It is a fine idea anyway - I sometimes find old foam body boards and cut these up for padding.

My antifoul doesn't like being out of the water for more than a month or two. If possible I would thin the antifoul by sanding if it is getting old before it gets hard with extended time on the hard.

But ensure you find your bulkheads, look for a a central spine if there is one. My boat has a 5mm spine running under the floor from bow to stern. It means I can support her anywhere but most cats don't have that - just support them at the bulkheads, or as close to as possible.

Some photos of the boat and its interior structure and the lift as well would help produce better advice.

cheers

Phil

[HodagSailor]

FWIW I have my 28 foot 11,000 lb. cat on a boat lift. The hull is solid FRP without foam core, and with added fiberglass thickness in the areas of the 4 support pads. Despite this there was enough hull flexing to crack a support rib.
Increasing the dimensions and reinforcement of the ribs along with enlarging the size of the pads will hopefully prevent any further significant flexing.
No anti-fouling paint, and I can get under it for cleaning.

[HodagSailor]

Here's some pictures:

[Gpryce]

I have my 36' Fountaine Pajot Mahe on a boat lift. I also had it's predecessor a Fountaine Pajot Maldives (32') on a lift. The lift cradle beams are located under the bulkheads, there's pivoting pads with bunkboards fore to aft, the boards conform to the hull shape. The end result is much like a boat (or min this case a pair of boats) sitting on a trailer.

[HodagSailor]

I like your set up.
I often have a lot of side current at my lift, pushing my boat into the vertical guide posts, which then are supposed to the center the pads under my hulls as the lift comes up. As you can see in the attached schematic, my hulls are quite flat on the bottom, so we went with single flat pads, counting on the guide posts for centering.
However, tightening up the guide posts to the vessel sides makes ingress/egress a bit more challenging in side winds/currents.
Switching to two pads which can adjust to the hull curvature and center the vessel as the lift rises makes sense.