Different to a Monohull
Multihulls are difficult to tack because of the high turning resistance of the long narrow hulls. The rudder stalls easily causing a braking effect if the tiller movement is too sudden and it is most important to have enough speed going into the tack for the boat to carry its way through the wind until the sail fills on the new tack.
The rudder will also stall when sailing offwind if the bow submerges and lifts the stern out of the water during a gust or a gybe. Again, the long narrow hull makes this feature much more noticeable than in a wider monohull boat.
In all weathers tacks should be smooth but firm, with particular care taken to maintain speed in the second half of the tack.
Gybes should be co-ordinated so that, when the sail crosses to the new side, the power comes on as smoothly as possible, to prevent the stern lifting, stalling the rudder and reducing control.
Light Winds [0-3 knots / force 1]
TACK - Push the tiller gently to no more than 45 degrees to turn into the tack.
As you go into the tack, pull the sail in a little then, as the battens pop over, ease the boom out 2-3 feet and centralise the tiller. Wait for the boat to pick up speed, which usually takes 5-10 seconds, and gently sheet in as full speed is reached. Don’t be tempted to try pointing up towards the wind again too soon, as the boat is initially sliding sideways and this will only be exaggerated if you steer to turn back up into the wind. With the tiller central, the boat will bear away and pick up speed - listen for the wake - and it can then be brought back on course.
If the battens won’t pop across reach behind and give the two falls of the mainsheet a sharp jerk.
GYBE - If you are on a reach, the turn should be smooth, not sharp. If you are sailing dead downwind the boom can be pulled across with the two falls of mainsheet behind the sailor or with special gybing lines attached to the kicker boom in front of the mast. Make sure the mainsheet does not droop and catch in the rudder T-bar and, after tacking or gybing, make sure the sail is set properly by trimming and adjusting until all the telltales are flying across the sail horizontally.
Medium Winds [4-10 knots / force 2/3]
TACK - To turn into the tack, push the tiller smoothly but firmly to 45 degrees and pull the sail in. As the battens pop across, ease the sail slightly, so that the boom end is over the corner of the transom. Straighten the tiller and wait for the boat to pick up speed then concentrate on pointing the boat as close to the wind as possible whilst making the telltales on the sail fly horizontally.
GYBE - If you are sailing a reach, the turn can be sharper. If you are sailing a run, the sail can be pulled or left to blow across but make sure the mainsheet is not slack as it will catch in the rudder T-bar and is difficult to free.