I was recently asked the question, “Which is windward and which is leeward?” On the surface, it is a basic question, but there are some circumstances where the answer is not obvious. It is also quite important since the tack a boat is on is based on which side is windward and which is leeward. The rule here is the definition of Leeward and Windward found in the Definitions section of the rule book.
Leeward and Windward
A boat’s leeward side is the side that is or, when she is head to wind, was away from the wind. However, when sailing by the lee or directly downwind, her leeward side is the side on which her mainsail lies. The other side is her windward side. When two boats on the same tack overlap, the one on the leeward side of the other is the leeward boat. The other is the windward boat.
Tack, Starboard or Port
A boat is on the tack, starboard or port, corresponding to her windward side.
Windward
See Leeward and Windward.
(click on the diagram to see a larger cleaner version)
In the diagram, we see six boats. If we start with the yellow boat, the situation is fairly straightforward. Yellow’s port side is away from the wind, so port is the leeward side and the starboard side is the windward side. The boat is therefore on starboard tack.
The red and green boats are approaching each other at position 1 with red on port tack and green on starboard tack. We can tell this since the wind is coming over the port side of the red boat and the starboard side of the green boat. At position 2, they have both headed up. Their windward and leeward sides have not changed. At position 3, they are both head to wind and exactly parallel. Again, the windward and leeward sides do not change. According to the definition, the leeward side when head to wind is the side that was away from the wind until the boat headed up, so the starboard side of red continues to be the leeward side, while the port side of green was away from the wind and thus continues to be the leeward side. Even though both boats are head to wind, red is still on port tack and green is still on starboard tack. At position 4, they have both crossed head to wind. They have not completed their tacks but there is a new side away from the wind – therefore a new leeward side and a new tack. Now, green is on port tack and red is on starboard.
The orange boat is sailing directly downwind. There is no side away from the wind, but the leeward side is the starboard side since that is where her mainsail lies. She is therefore on port tack.
The blue boat is sailing by the lee. Her mainsail is still on the starboard side. The starboard side is her leeward side even though the wind is also coming over it. She is on port tack. The white boat is sailing completely parallel to her but her mainsail is on the other side. The starboard side is her windward side so she is on starboard tack.
Windward and leeward may not always appear immediately apparent, but by keeping these scenarios in mind, you can make sense of the situation on the water.
Match racers who would like to see such more complicated scenarios around this subject should go to the ISAF website and look at the Rapid Response Match Racing Calls 2011/003 and 2010/006. The can be found at http://www.sailing.org/raceofficials/rapid-response-calls.php.
© Copyright 2012 Andrew Alberti