HI Chaps,
Thought I'd share a 2018 change to the RRS Rule 17. This pertains to your obligations at the start lines when it's a reach to the first mark.
It came into effect after they published the last Blue book, so this is an addendum that is not in the latest Blue Book RRS
It's interesting that it is a complete cut and paste of this rule. The existing rule 17 refers to obligations when creating an overlap from astern, a different topic entirely and now apparently moot.
Thought it might be of interest!
Cheers,
SB

Part 2
Section B
Rule 17

Rule 17 is deleted and replaced by ON THE SAME TACK BEFORE A REACHING START
When, at the warning signal, the course to the first mark is approximately ninety degrees from the true wind, a board overlapped to leeward of another board on the same tack during the last 30 seconds before her starting signal shall not sail above the shortest course to the first mark while they remain overlapped if as a result the other board would need to take action to avoid contact, unless in doing so she promptly sails astern of the other board.

Umm Shaggy,
Might you be talking about the Windsurfing Rules? I note that the rule you quoted talks about 'boards' not 'boats'.