"It seems to me the rule assumes this overlap between each mark. The term "gate" is not defined. Rule 28.1.c refers to passing "between the Marks"."

Guys, you're trying way too hard to find a problem here. I'm a certified RO, and have enough on-water experience and have been to enough seminars to tell you that, up to and including Olympic and A-Cup ROs and judges (I've worked with several of each), overlapping zones at gates is NOT acceptable.

Mike