It's often very very difficult to breach that layline procession of starboard tackers from the port tack. Yesterday I tacked in front of a stbd tacker, was well passed the new heading but still below it recovering from the 'fall off' when I was hit from behind and stopped. The trailing boat simply sailed straight through me, out the other end and continued on???
I happened to be in front of a very good sailor from up north at the time, and I thought I had him but unfortunately, (for me) the fat lady had yet to become vocal and another good result went south. <img src="http://www.catsailor.com/forums/images/graemlins/frown.gif" alt="" />
If you have stopped your tack midway, like Tikipete did, the other boat would have fouled. Its not the right way of doing it, but using the tacticat rules system you will gain a spot. I usually do this to bots and not to real people.