Many catamaran sailors who move up to sailing catamaran sailboats after sailing dinghies will find they need to develop new techniques for tacking. Catamaran sailboats are not difficult to tack, but if you attempt to tack by just throwing the tiller over, you probably won't do well.
Dinghy sailors have refined a sailing technique called the "roll tack" which vastly improves speed coming out of the tack. A lot of catamaran sailors are not aware that you can roll tack your beachcat as well. Read more to find out how.
1. Have some speed so the boat will respond to the rudders.
2. Warn your crew to get ready, cause he/she has a role in the tack
3. Announce the tack and move your weight and the crew's weight to the
windward rear corner casting as you begin to slowly but firmly push the
rudder to 45 degrees. (Notice there were three things going on
simultaneously in step 3.)
4. Tighten the main sheet as the hulls head to weather. Continue to
hold the tiller in 45 degree position.
5. Don't move your weight until the boat goes through the wind. As soon
as the main "pops" to the other side, and it should make some noise, the
crew scrambles to the opposite front corner casting and you release about
6-8 inches of mainsheet as you scramble in and under the sail.
At this point you have tacked and need only to recover. As you move
under the boom, hand yourself the tiller extension on the new side. The
forces on the rudders are nearly zero, so be careful not to wiggle or
move from 45 degrees yet.
6. As you hand yourself the tiller extension, grab the mainsheet with
your other hand and move forward next to the crew on the front corner
casting. As you move, bring in tension to the mainsheet.
Notice I ignored what the crew does with the jib. I'm convinced it
doesn't make any difference what the crew does or when with the jib. The
extremes are (a) no jib at all, in which case the crew cannot do any harm
whatsoever; and (b) the crew forgets to do anything and the jib
backwinds, which is the "standard" for tacking. My crew is instructed to
release the jib at step 3 and to take up the slack for the new side
during step 4. Then she tensions the jib during step 5. We usually
overtack by about 30 degrees and I have to do some serious correcting to
get point the right direction. Maybe we should practice more??
The reason you move your weight to the rear corner casting is the form a
pivot point for the boat to turn on. Moving two parallel hulls around a
circle is very difficult (hence the differential on cars). The reason
for moving the crew weight forward is to prevent flipping over backward.
The reason for moving the skipper weight forward after the tack is to get
the transoms out of the water so the boat will accelerate.