Start line colision

Originally posted by laser193713 ...if someone gains an overlap from behind (overtaking), in most normal sailing situations, then you are highly likely to be the right of way boat.

Just not true though.

Three possibilities.
You overtake from behind and to windward. You are keep clear boat.
You overtake from directly behind and to leeward. You have right of way but may not sail above *your* proper course, and must initially give the other boat room to keep clear.
You overtake from behind and well to leeward. You have right of way and no restrictions on your course.

In paper/electronic rules discussions there is a lot of virtue in quoting rule numbers because it defines which rules you believe apply, and saves quoting the entire text of every rule all the time. In an on line discussion the rule book is always available to all the participants.

By contrast on the water quoting numbers is not usually very useful.



Edited by JimC - 04 Aug 15 at 12:24pm

Take my IC, which has an underslung rudder and a pointed stern. If we get too literal about this if a boat coming from behind makes contact 5mm to leeward of the point then I failed to keep clear of her under RRS11*. If she makes contact 5mm to windward of the point then she failed to keep clear of me under RRS11. Only if she makes contact *exactly* on the very tip of the stern would it be a breach of RRS12. Obviously that's a nonsense.

So there must be a zone around a boat that constitutes not keeping clear, and it must be variable depending on boat and conditions. If you want another situation where being excessively literal starts becoming a nonsense, consider if my canoe makes contact with the leeward side of the windward hull of a catamaran.



Taking that example: people might be aggrieved if DSQd with no contact under RRS 12, but they shouldn't be. However sometimes you know that a rule has been broken, even if you can't define exactly when. Take my example above of the boat that contacts the stern of my IC 5mm to leeward of the point. Do you penalise me under RRS 11, or do you penalise the other boat under RRS12 on the grounds that although you can't be precise about exactly when he failed to keep clear under RRS12, he can't have got in that position without breaking it?


*yeah, OK room to keep clear comes into it, but not the point at issue




Edited by JimC - 04 Aug 15 at 1:01pm

"You can't ram people up the chuff" sums things up nicely, thank you!

Originally posted by JimC The trouble with that ultra literal interpretation is that it suggests that if boat A is 1 mm astern of boat B then A is keeping clear of B since B can change course in either direction without making contact.  I don't think Ed was really trying to buck Case 30. However, if we go to case 30 and Case 88 it seems that a bit more than that is required. In particular Case 88 says:  ‘Keep clear’ means something more than ‘avoid contact’; otherwise the rule would contain those or similar words.   The implications of that seem to me to be are that if the keep clear boat is so close to the other boat that ordinary relative variations in speed through natural changes in wind and water are liable to to bring them in contact without action by the crews then it is not keeping clear. Well the Case 50 guidance is about reasonable apprehension of collision, rather than probability. So it seems to me that on small boats on flat water with a steady wind that distance might be a moderate number of inches, on big boats in a rough sea it might be several feet, Yeah  Case 21. but either way if astern establishes an overlap on ahead's rudder while she is within that sort of range then she was failing to keep clear immediately before establishing the overlap, Not happy with this:  it sounds a bit doctrinaire.  I think you need to go through the Case 30 reasoning. Maybe if you added 'and there is contact' it would work better. and the subsequent collision would not have occurred without that rule breach. Rule breach is relevant to exoneration for the ahead boat not keeping clear.  May be relevant to a rule 14 breach, but perhaps not so much. But I am probably wrong!  Why?  Your batting average here and in SA is looking pretty good at the moment.