I think we touched on this in another thread by I can't find it. We sail mostly on lakes, so we see shortened courses fairly often due to changing wind conditions. We were racing at my local club yesterday and the race committee set a standard course with a windward and leward mark (A and C) and finish line roughly in the middle of the course. The course called for two laps with an upwind finish. We had some nice wind at the start that quickly faded (naturally, right at the start signal). Given the time that had transpired the race committee decided to shorten course. We're leading the fleet and they pulled up and set anchor to the left of C-mark and we had completed a little more than 2/3 of that leg from A to C. We ran into this a couple of weeks ago at my club and the fleet sailed directly through the line, ignoring the "proper" way to round C mark. I was about the third boat in that mixed fleet race and, unsure of exactly how we should finish, followed suit and we were all scored.

As I approached the finish line yesterday (in the lead this time) I rolled my eyes and cursed myself for not knowing the right answer on how to finish this race but given that I was scored last time by ignoring C as a mark, I sailed straight down the course and through the line (what was C mark now to starboard). I watched for the horn on the committee boat, saw her lift it up and hold it in the air (for what seemed like an eternity) and the horn went back down without a sound. I spun the boat hard, came back across the line, rounded C-mark, and crossed the line in the opposite direction and got the horn (whistle). Some boats behind me finished straight through, some others finished by rounding the mark first.

One extremely knowledgeable sailor (who was the second boat to approach the finish) insisted that the proper finish was the sail "from the direction of the last mark" straight through the finish line as per the how a finish line is defined in the RRS and how I had attempted to finish initially. A protest was filed and we'll hopefully get this resolved (and get the RC back to the right of the mark so this question doesn't have to come up again!). I spoke with the race committee after the race and they explained they started setting the shorten course this way because someone complained that by setting the finish line to the right of the mark favored those that were coming down the right side (as you are sailing) of the course. I can probably see this argument if the race committee is very late getting the shorten course established...but it's not much of a difference. To compensate, they started setting a shorten course to the left of the mark (as it is being approached) thinking that the fleet would need to round the mark first and it would eliminate the favor of extending the target (the mark or the finish line) to one side more than the other. Hopefully this will be an opportunity to get them to shorten on the right side (mark to port) of the mark so there will not be any question.

So, is it correct to sail straight through the line and ignore C-mark or round C-mark first and then finish as part of your rounding?