During a recent Wednesday night mixed dinghy fleet race I encountered a boat that was vehemently convinced that they should be rounding the marks to starboard or "clock-wise" in direction. I was very confident at the time that I was correct and continued to round the marks to port or "counter clock-wise". I have attached the rule I believe applies to this situation as well as applicable statements from the NOR and SI. The opposing statement is as best i can remember it, the side of your vessel indicates which direction all course marks should be rounded. I have never heard this before and additionally cannot find any mention of it in the RRS, NOR, SI, ISAF case book, or ISAF Q&A service. Additionally, took no action to notify the racers to round the marks to starboard. Am I right or have I overlooked something very obvious? RRS-28.1 A boat shall start, pass each mark on the required side in the correct order, and finish, so that a string representing her wake after starting and until finishing would, when drawn taut, lie on the required side of each mark and touch each rounding mark. She may correct any errors to comply with this rule, provided she has not already finished. After finishing, a boat need not cross the finishing line completely. NOR-"Courses will be windward/leeward, or triangular courses at the discretion of the RC, with all buoys left to port, unless instructed otherwise the SI or RC" SI- 'Marks will preferably be "left buoys to port"'