NavList:

Graham,

Here is a tip from SailNet.com listed under Close Hauled Tactics that should be of interest to you.  

After a ballasted sailboat has reached its maximum speed, its weight will allow it to coast for brief periods without a significant reduction in speed. You can take advantage of this ability to coast by steering the boat on a scalloping course to windward, alternately pinching to windward for a couple of seconds, and then falling back down to a close-hauled course to get the sails driving again and maintain boatspeed. By steering a scalloping course, you will be able to drive the boat slightly closer to windward than your opponents. If you are slightly ahead and to leeward of another boat, it will enable you to point higher than the other boat, and force it to tack. When steering a scalloping course, it is important that you use smooth, gradual movements of the rudder to steer the boat, because abrupt or large movements of the rudder will kill boatspeed during the coasting phase.