I think the problem with questions like this is that there is insufficient information to come up with a definitive answer - people then add factors to the situation to make it fit their chosen answer.
>I think the problem with questions like this is that there is insufficient information to come up with a definitive answer - people then add factors to the situation to make it fit their chosen answer.
I thought there was enough information and said what I would do, turn enough to make the boat not worry about how close I would pass. It's simple overtaking boat keeps clear, forget any angles, there is no other option unless you intend to change course to a completely different angle anyway.
It's only an overtaking boat situation if the faster boat started out in the 'stern light sector', and the windward boat has not altered course since then. Of course the leeward boat may not want to alter course, as it would probably involve a gybe or the risk of a gybe, while the windward boat can head up without any such problem.
It's an interesting one, because yachts do not naturally sail a perfectly straight course in such conditions, it pays to keep an eye out behind in case the helm bears off into the path of a leeward boat.
I would expect the boat sailing 10deg off dead down wind to be going significantly faster than the other if they were similar size.
You also find that sometimes one boat is actually being sailed and the other is on autopilot. The boat being sailed will follow the wind more than the compass, and along our coast it would be rare for the wind not to shift more than 5 degrees several times in the time it takes these two boats to come together from over the horizon.
And you may find that one person's idea of not keeping far enough clear is another person's idea of getting close enough to take a nice photograph.
The other thing is that the two boats will mesmerise each other and they will both get in the way of a cross channel ferry or something.
Personally, I'd be sailing my boat, not on autopilot, so altering to avoid the other boat would probably just happen, because getting too close to other boats is generally just slow.
The original question was “to collide or not to collide “
Crossing or overtaking does not matter. If you are in one of these boats are you willing to hold to your perceived right or would you give way to avoid a collision.