Two sailboats are approaching the start line on starboard tacks with 30 seconds to the start.  The windward boat might think he has the advantage with the clear air, but if he hasn’t completely thought out his tactical situation he might find himself in a world of hurt.  The leeward boat actually controls this situation.  The leeward boat has tactical control in that the windward boat must keep clear of him even if the leeward boat comes all the way up to head to wind.  The leeward boat can keep pushing up the windward boat as long as the windward boat has time to react.  That is why you can hear “Comin’ Up, Comin’ Up” during the start the sequence.  The leeward boat can and will push the windward boat over the start line early.  The Race Committee Boat will not save you either.  If the windward boat replies that it can’t go up because of the RC Boat, the leeward boat has to give the windward boat room to avoid a collision, but the leeward boat has a valid protest and the windward boat needs to start his 720’s.  Note that at the end of the race, the windward boat has the advantage.  With two overlapping boats finishing, the leeward boat has to give the windward boat mark room to finish.

If you are still a little confused about these rules, here is an excellent website which gives case studies and how the rules apply:  http://game.finckh.net/indexe.htm

Here are the case studies for the start:  http://game.finckh.net/situat/tit_gbr/start_e.htm

(This website might not work on a mobile device)