Could you????

I think you'd be in trouble with copyright... You'd have to write a complete set of new rules which had nothing in common with the ISAF ones, then you'd have no backup from the RYA, appeals process etc etc. Then the racing rules also have a legal presence because they govern conduct between boats racing... It seems awfully unwise to me. What rule is so dreadful that you want to change it?

Nothing in paticular, I am just a little concerned at the way some of the rules are now being phrased to remove the discretion of the sailing clubs from governing their own races, and wondered how tightly bound up in the ISAF game we all are.

The cynical answer is that most sailors appear to ignore the rules in any case!

The correct answer to your question is found in rule 86.1b

"Sailing instructions may change a racing rule but not rule 76.1, appendix F, or a rule listed in rule 86.1a"
86.1a lists the definitions, the introduction, sportsmanship and the rules part 1,2,7, rule 42,43, 70,71, 75, 76.2, 79 or 80, any appendix that changes one of these rules, appendix H or N, or ISAF Regulation 19, 20, 21, 22

So you can change any of the rules on how you start, sail or finish a race.

I believe that it would be dangerouis to change a rule of part 2 unless you can guarantee 1) that sailors from your club never race anywhere else, and 2) that no outside boats ever race in your club. The rules governing what boats should do when they meet should be so ingrained that the sailors response to any situation should be almost a reflex. Not a good idea to change any of these.

Personally I believe that the movement towards universal racing rules, originating, in 1874,  following an initiative by a club of which I am proud to be a member, is not something to be abandoned lightly. As it is, a sailor should expect that the sailing instructions he has to read before any event are written in a standard format so that the Race Committee's intentions are clear.

What rule do you want to change? For what reason?

Gordon