For a designer to specify a size and depth he must have those variables filled in.

Does a catamaran have a keel. Some high performance catamarans from manufacturers like Outremer Gunboat and HH make incredibly fast catamarans that can achieve speeds in the high teens and low 20s under ideal conditions. A catamaran stays stable since it has a wide base it does not have a deep keel as on a monohull. A catamaran is a boat with two hulls and a bridge between them.

A catamaran does not get the same benefit from having a keel. Furthermore I am one of the few designers who has fitted LAR keels and boards to the same hull on Strider Sagitta and Banshee and then sailed them against each other. A sailboat needs a keel to avoid capsizing when the sails fill with wind.

This is less the case on deep finely shaped performance catamaran keels. Foils are designed to create lift and to minimize drag. You have to be very aware of the wind conditions when arriving or departing a marina dock.

The draft on most keeled catamarans is deeper than the draft on daggerboarded cats. If you are looking for a rule of thumb the shallower the keel the more area it needs to compensate for the reduced effectiveness So if the designer cant go down he must go long. Over the last 30 years I have owned five cruising catamarans with keels nine with daggerboards and one with one centerboard.

Larger catamarans have an engine in each hull so they can still be highly maneuverable and offset the wind effect. Lets look at the two schools of thought on this subject. Personal watercraft have come a long way over the years and the small one two three and four-person catamarans have come a long way as well.

The general perception that catamarans. Then the next would be to have keels. In the case of these boats it comes back to daggerboards.