So you booked this cat for your next charter cruise. Problem is, you are a monohull sailor... Here is a quick guide, with all you need to know. When you are done, you definitely want to check this web site
The main difference with a monohull is that a cat has TWO engines, one in each hull. Because the engines are located very far apart from each other, it makes maneuvering extremely easy - much, much easier than a single engine sailboat. A cat can literally pivot around its vertical center axis, i.e. turn on a dime, regardless of its size. I have maneuvered a 47ft. cat in very, very tight quarters... did not hit a thing around the boat, whereas I would certainly have chipped some little gelcoat with a mono. Here is a quick guide to maneuvering at slow speed:
Cats do not go upwind as well as monohulls, although they have much improved lately in that department. You won't get much closer than 45/50¾ to the wind, going upwind. If the sea is choppy and you are on a smaller cat, like a 38ft. the yawing will be a little difficult - which is why you see so many charter cats simply motoring upwind. If you still decide to sail, bearing off a couple of degrees will usually alleviate the motion.
Now, going off the wind is what the cats are all about. Do not necessarily try to go dead downwind, but if you do, you probably want to be under jib or genoa only. A more efficient point of sail is between 120¾ and 150¾ at which you should sail at a speed of about 50% of the true wind. Needless to say, you will smoke quite a few monohulls there!
One of the cats' problems is that there is no heeling to give a feel that the boat is over-canvassed (the good news is that the bowl of fruits you left on the table won't go flying and smash against the stove!). If it becomes very windy, things can become a little hairy. So you have to be careful and stick with the information given by the charter company's briefer.
The rule on a cat is that one starts de-powering the main sail using the traveler, because it has a very wide span, and it can be let go very quickly. Other than that, usually, on a 40ft., you should put the first reef at around 20kts. of wind, and the 2nd. reef at 25kts., and the headsail should be completely furled, to be on the safe side. Reefing has the same procedure as a monohull.
Jibing is the same procedure as a monohull... but tacking is different and can be frustrating. Here are the secrets to an efficient tack on a cat:
Here are some more secrets: