Sailing a scratch race (informal start) I rounded the leeward mark and then came up to speed on a port tack, then tacked to starboard. 20 seconds later, I looked right, up wind and turned hard to avoid a boat coming in from my right, the windward side! We touched, but no damage.
What happened?
Racing on the wind, on a starboard tack, the "threat" is a port tack boat aslo on the wind. You look through or under your sail to see the threat. The next likely threat is someone ahead who gybed and is coming head-on. Looking ahead and to leeward is sensible and safe. Usually.
In this case, someone NOT RACING was "reaching" down the course on a starboard tack. LESSON: keep looking, especially when cruisers are about. Every direction.
Now, in the rules, there is no reaching: you are either "on the wind" or "off the wind." Read the definitions in the NIA rules, which can be found linked through the Archives at the opening page of DNAmerica.org. in this case both boats were "on the wind" as the true wind was forward of abeam.
As the two boats approached each other, what should have happened? If two boats are on the same tack on the wind, then the windward boat should stay clear of the leeward boat. But the windward boat "swore" I was on port tack. The sight picture for him would be a boat closing on his lee side (similar sight picture when the closing boat is on a port tack). He saw me on a port tack and expected me to avoid him. I never saw him, and I was leeward boat and on on a starboard tack. CONFUSION!
Fortunately both boats implemented the fundamental save-yourself rule: OSTA (also known as UOTA)
OS is "Oh, S**t," UO us "Uhh Oh" TA is "turn away!" At the last instant, both boats turned away and the collision was a glancing blow only.
Share your near miss or worse closet encounters! And keep looking for oncoming boats, regardless of your right-of-way status.