March 2011 - Crossing Too Close

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March 2011 - Crossing Too Close

I finished last month with a situation where a boat pushes the limits. This month I am going to cover a much simpler rules situation that leads to many very difficult protests.

(click on the diagram to see a larger cleaner version)

In the diagram the green boat is on starboard tack. The red boat is slightly ahead and tries to cross on port. The only two rules that really apply here are rules 10 and 14.
When boats are on opposite tacks, a port-tack boat shall keep clear of a starboard-tack boat.

A boat shall avoid contact with another boat if reasonably possible. However, a right-of-way boat or one entitled to room or mark-room
(a)        need not act to avoid contact until it is clear that the other boat is not keeping clear or giving room or mark-room, and…

Red, as the port tack boat, is required to keep clear of green on starboard tack. Green is required to avoid contact if reasonably possible. Green is not required to act until it is clear that red is not keeping clear.
In this case, green decides that red is not keeping clear, so she bears off as she feels the rules require –and because she doesn’t want to have a collision.. She then protests. Red maintains that she was keeping clear and would have crossed even if green had not borne off. Careful measurement on the diagram would allow us to determine whether they would have made contact, but we don’t have that luxury in real life. This will become a controversial and difficult-to-decide protest. Did green have to bear off? Was red too close? – Even a simple port/starboard isn’t as clear-cut as many assume.
There is guidance in the ISAF Casebook for cases like this – in this instance in Case 50. The full case can be read at
Case 50
When a protest committee finds that in a port-starboard incident S did not change course and that there was not a genuine and reasonable apprehension of collision on the part of S, it should dismiss her protest. When the committee finds that S did change course and that there was reasonable doubt that P could have crossed ahead of S if S had not changed course, then P should be disqualified.

Rule 10 protests involving no contact are very common, and protest committees tend to handle them in very different ways. Some place an onus on the port-tack boat to prove conclusively that she would have cleared the starboard-tack boat, even when the latter’s evidence is barely worthy of credence. No such onus appears in rule 10. Other protest committees are reluctant to allow any rule 10 protest in the absence of contact, unless the starboard-tack boat proves conclusively that contact would have occurred had she not changed course. Both approaches are incorrect.

A starboard-tack boat in such circumstances need not hold her course so as to prove, by hitting the port-tack boat, that a collision was inevitable. Moreover, if she does so she will break rule 14. At a protest hearing, S must establish either that contact would have occurred if she had held her course, or that there was enough doubt that P could safely cross ahead to create a reasonable apprehension of contact on S’s part and that it was unlikely that S would have ‘no need to take avoiding action’ (see the definition Keep Clear).

In her own defence, P must present adequate evidence to establish either that S did not change course or that P would have safely crossed ahead of S and that S had no need to take avoiding action. When, after considering all the evidence, a protest committee finds that S did not change course or that there was not a genuine and reasonable apprehension of collision on her part, it should dismiss her protest. When, however, it is satisfied that S did change course, that there was reasonable doubt that P could have crossed ahead, and that S was justified in taking avoiding action by bearing away, then P should be disqualified. (Italics added.)

For green to win her protest, she has to establish that “she had a reasonable apprehension of contact”. For red to have the protest dismissed, she has to establish that “there was not a genuine and reasonable apprehension of collision”.

The skipper of green is probably near the stern and a full boat length away, while the skipper of red is very close to the gap and has a really good view . The comfort level and experience of the two skippers will probably affect whether green does bear off. Experienced skippers may be used to really close crossings. If the skipper of green is comfortable that the skipper of red does not want his boat to be hit, this will help reduce his apprehension. An inexperienced skipper of green may be less comfortable with the close crossing and have more of an apprehension of collision (the protest committee will have to decide if it was a reasonable one). On the water as they approach, a hail of “Hold your course” from the skipper of red might help to increase green’s comfort level. It is not a required hail (there are only three required hails in the rule book) and it has no official standing but it can be useful to reduce green’s apprehension of collision.
This is a risky situation for red. There is no risk of green being disqualified in a protest, but there is a reasonable risk of red being thrown out. I think the case and the rules support red being thrown out in the diagram as shown (I measured they miss by inches), but it has been pointed out to me that in real life protest committees are reluctant to disqualify so red may survive a move that I suggest you avoid.

© Copyright 2011 Andrew Alberti
Posted: 3/1/2011 2:09:08 PM by Andrew Alberti

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This page provides links to a set of articles original published in Kwasind magazine. The versions here include animated diagrams. The original articles can be found within the original magazines which are available online back to January 2007. 

Articles before December 2020 are based on the Racing Rules of Sailing 2009-12 or 2013-2016 or 2017-2020 and have not been updated to reflect the changes that apply as of January 2021 with the publication of the Racing Rules of Sailing 2021-24. A copy of the new rules can be found on
Andrew Alberti has been writing these monthly articles in the Kwasind since early 1997.  They explain the Racing Rules of Sailing. Andrew is an International Judge and National Umpire. He is a member of the Sail Canada Rules and Appeals Committees. The interpretation of the rules contained in the articles is Andrew's and not that of the RCYC or any of the committees he sits on. 

Send your questions to Andrew at [email protected].


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