Wessex Winter Warmer
Richard Thompson expressed the idea that the new rule 18 (Mark Rounding) now keeps all the other rules applicable and only allows "room to sail to the mark"
Since rule 19 seems to use the same principal, I have heard it expressed that when two boats come up behind an obstruction the windward boat has to go to windward. Two Calls F2 and H1 refer to the situation and it was interesting to look at them and try to get some guidelines as to how to apply the calls on the water.
My conclusion was that, in the event of a protest, the courses of the leeward boat at the point when the windward boat has to alter course to avoid the obstruction is a critical fact. If she is steering to pass to leeward of the obstruction then I think the windward boat is entitled to alter course to leeward and can expect that room will be given. If she is steering at the stern of the obstruction the windward boat is probably not entitled to room and will have to keep clear as windward boat (asuming that there is room) What she cannot do is push the windward boat to windward of the obstruction and then pass to leeward of the obstruction herself. (or can she?)
The problem with the whole scenario is that even if the middle boat is clear ahead as in call H1 the act of bearing away can create an overlap. If the bear away was too early and there is room for the now windward boat to go up she must (presumably) do so. And as she put herself there there is no need for the leeward boat to give her room to go up. So we have a judgement call as to how early the middle boat had to begin altering for the obstruction. (and you won't find that anywhere in the rules)
Maybe it comes down to what is an inside boat. In which case the course of the windward boat assumes more importance. If she is diving down she probably, at some point, gets to be the inside boat. Call F2 says she becomes entitled to room when she can no longer luff to windward of the obstruction. If contact is made with the leeward boat before this time then she failed to keep clear as windward boat. If she gets committed before failing to keep clear then she has to be given room. And the ability of the outside boat to do this will depend on the extent of any overlap.
If, once she is committed to windward of the obstruction, the leeward boat then chooses to pass to leeward of the obstruction has she failed to give the inside boat room or is she just exercising her right to pass either side of the obstruction?
Perhaps there is a need for the two calls to be brought together and for there to be a more expansive explanation.