Skiff sailors are the least likely to obey the rules. If a 15ft dinghy like the Musto described above is 53ft from the mark coming straight down and a F18 53ft from the mark is coming from wide, the F18 has established it's rights as per the rules, the dinghy must go behind the F18 unless the F18 is not sailed with proper seamanship.
The rules state you have established your position when you hit the zone, this is the hardest part of the rules because it doesn't matter if that Dinghy is going 5 times faster if he cannot round without affecting the F18 he must do a 360 or be disqualified. Just as the other ex dinghy sailor in this thread should be disqualified for saying he deliberately caused a collision with the inside boat and didn't do a 360 after he felt they had taken enough room.