I think the "problem" with the "Leeward boat has right of way" rule here is, the boat coming upwind (the leeward boat, or ROW) has the best view of what's going on, as he's looking upwind in the first place and he's not got a big spinnaker blocking his view.
I don't really see this as a spinnaker issue, or even a catamaran issue, since the same problems exist with jibs and on monohulls. The problem seems to be the speeds involved - it's possible to get in trouble
fast. At higher speeds, you need to look and plan farther ahead.
The 'burdened boat' is coming downwind with the spin up, blocking at least part of his downwind view, and the skipper is most likely looking upwind for a puff to chase, not always looking downwind for traffic.
A boat must keep a good lookout, spinnaker or no. If the skipper ignores downwind traffic to watch upwind puffs, then he's likely to get into trouble no matter what the rules say.
If the ROW boat was at one time well clear, but then tacks, and the burdened boat never see's him tack, and now the ROW is in the spinnaker blind spot, well, it can get very interesting, very quickly.
If a windward (let's assume port tack) boat sees a leeward port tack boat coming upwind disappear behind his spinnaker, he needs to watch for it to appear again. If it doesn't, he's got to actively look to see where it went. If one has to periodically round down and/or slack the chute to keep an eye on leeward boats, then that's what one must do.
I know when I'm the ROW boat, going upwind, I never assume the spin guy coming down sees me, and I'll gladly tack to get out of his way...more so if it's blowing and he's hauling butt. I don't want to end up "Dead Right".
That's wise. At the point where you have reasonable apprehension of contact if you don't take avoiding action - take it (see ISAF Case 50). Then protest. Rule 14 (and common sense) require you to attempt to avoid contact.
I think it goes to the "avoid a collision at all costs" rule.
Well, Rule 14 doesn't say "at all costs". It says "A boat shall avoid contact with another boat if reasonably possible". Watch out for other boats, plan ahead, and avoid contact reasonably.
Regards,
Eric
