I would stress that this question is not part of a protest nor will be, but is an attempt by be to understand the 3 potential rules that could bein force as I cannot finsd an example of this incident that comes from having two different types of sailing craft with different limitations off the wind
In a mixed boat race fleet , I was sailing in 8 knots wind, down wind, almost by the lee, port tack with large spinnaker up, port pole.
In the race was a sport boat asymetrical spinnaker that had been zig zaggin down wind, he came initially un observed from astern on the port quarter, then rapidly aiming for our mis ships, yelling starboard
Points
Yes we were on opposite tacks thus as I was on port he had right of way is this correct rule 10
But in effect was the overtaking boat does this matter or negate the above
His gybe had been quick his speed far greater than mine thus impossible for me to gybe with an inexperienced crew in a reasonable time to take avoiding action rule 14/15
He could have hardened up a fraction come behind me easily, and argued a protest but that action would have only cost him a few seconds in a 12 hour race
Instead purposely made our boat undertake a crash gybe with out changing the spinnaker pole (Dip Pole) put the crew at risk and the resulting wrap was a disaster
Was room to gybe vilolated as for me there was no real option to manoevre either up wind or down wind!.
Created: Today 15:48 Active
When you race mixed fleets it’s important to know the sailing characteristics of other boats to ensure you can keep clear when required
The boats were on opposite tacks so you on port had to keep clear of the other boat on starboard. That means that S has to be able to sail her course (that is any course of her choosing) without having to take avoiding action (see definition of Keep Clear). If S had to take avoiding action then you broke rule 10.
There is no rule that requires an overtaking boat to keep clear simply because she is an overtaking boat. An overtaking boat may have to keep clear under one of the right of way rules but it is equally possible (as in this case) that the boat being overtaken has to keep clear under one of those rules.
You say "his gybe was quick" which suggests that the other boat gybed on to S shortly before the incident. Under rule 15 he was obliged to give you room to keep clear in a seaman like manner at the time he became right of way boat. Room is the space required by a competent but not expert crew of the right number (WS Case 103) so any lack of experience of your crew would not be taken into consideration - if you choose to sail with an inexperienced crew that is your problem. Furthermore you say that the boat was "initially unobserved" which suggests that you did not start to keep clear at the time the other boat became right of way. The room you have to be given is enough room if you react as soon as you become keep clear boat and not the room you need when you happen to notice that you are keep clear boat.
You reacted properly to meet your obligations under rules 10 and 14 (avoiding contact) and the fact that this cause problems seems to be down to the fact (as others have pointed out) that you were not keeping a sufficiently good look out to enable you to react as soon as you became keep clear and had you done so there would not have been problems. If a PC decided that even if you had noticed S as soon as she became right of way you would still not have had room (subject to the above caveats) to react in a seaman like manner then they would penalise S but from the way you describe things that does not appear to be the case.
You might have a defense under 16.1, if the asymetric did not hold a steady course, somewhat implied by your statement "then rapidly aiming for our midships" Any change of course by the right of way boat re-sets the clock on your time to keep clear.
It's easy to see when you are Umpiring but proving it in a protest hearing is another matter.
You were aware the sport boat was crossing gybes with you, so should have kept track of his, and other's, whereabouts.
Starboard over port yes, but the right of way boat has obligations and limits too.
Principal among these are providing ample room for give way boat to avoid fouling, and, when a boat is giving way cannot force a crash gybe.
Had you been watching, and found that the starboard tack boat altered course when you were keeping clear you would stand a chance of winning a protest.
The rule 16 obligation under Section B-General Limitations on the right of way boat to give room, ONLY applies when the r-o-w boat changes course. If that was your defense, you would need to show the r-o-w boat changed course and you kept doing everything possible keep clear, but failed because the changing course r-o-w boat exceeded her responsibility.
If it is of any condolence, I remember the exact moment in 1959 I learned port-starboard trumps windward-leeward. Damn Tony Zannotti :-)