May 2010 - Avoiding Collisions

placeholder image

May 2010 - Avoiding Collisions

I believe that the primary reason that we have right of way rules in sailing is to avoid collisions. Rule 14 is the rule that most directly addresses this topic.
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
(b)        shall not be penalized under this rule unless there is contact that causes damage or injury.



A boat has right of way when another boat is required to keep clear of her. However, some rules in Sections B, C and D limit the actions of a right-of-way boat.

This rule is really in two parts and actually addresses two audiences. The first talks to everybody “A boat shall avoid contact with another boat if reasonably possible.” All boats are supposed to avoid collisions. This is key to our sport. We aren’t supposed to be playing bumper boats. 

The rest of this rule is addressed to right-of-way boats or boats entitled to room or mark-room. Who is a right-of-way boat?   The preamble to “Section A Right of Way” describes this. It says that when one boat is required to keep clear of another boat then the other boat has right of way. The rules that require a boat to keep clear are rules 10-13 (Port-Starboard, Windward-Leeward, Clear Ahead-Clear Astern and Tacking) which are contained in Section A. Right of Way boats are therefore Starboard Tack boats, Leeward Boats, Clear Ahead Boats and boats not tacking (or when boats are tacking simultaneously, the boat on the right). Rule 21 also requires some boats to keep clear and therefore grants right-of-way. We are also talking about boats entitled to room or mark room (this is primarily rule 18-20).

So the rest of rule 14 talks to these boats. It says two things. First it says that these boats need not act to avoid contact until it clear that the other boat is not keeping clear or giving room. I am going to illustrate this with a simple diagram.

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

The yellow and green boats are both on starboard tack. The red and blue boats are both on port tack. Both starboard tack boats initially have a right to believe that the port tack boats will keep clear. By position 2, yellow can tell that blue is not going to keep clear. Yellow now has an obligation to keep clear. Green on the other hand may still believe that red is going to duck. Even if he doesn’t believe it, there is almost nothing that green do. If there is subsequently a collision in both cases yellow has broken rule 14, green has not. 

Rule 14(b) is a little unusual. It says that right-of-way boats will not be penalized for breaking rule 14 if the contact does not cause damage. If there is contact between yellow and blue that does not cause damage, yellow has still broken rule 14, but will not be penalized. If there is damage, yellow can be disqualified. Green has not broken rule 14, so the issue of whether she is penalized does not come up.

Finally I want to make a comment about the responsibility to keep a look out. Some people believe that if you are right-of-way you don’t need to keep a lookout. The appeal cases come to the opposite conclusion. 
ISAF Case 26 says “An important purpose of the rules of Part 2 is to avoid contact between boats. All boats, whether or not holding right of way, should keep a lookout at all times.” ISAF Case 107 says “This requirement means a boat must do everything that can reasonably be expected of her in the prevailing conditions to avoid contact. This includes keeping a good lookout, particularly in a crowded starting

line situation.” A recent Canadian case comes to similar conclusions. Right-of-way boats have to keep a lookout.

© Copyright 2010 Andrew Alberti
Posted: 5/1/2010 2:57:27 PM by Andrew Alberti

Trackback URL:

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].


166 Years of Tradition | World-Class Sailing | Toronto Island & City Clubhouse
After You Cross The Finishing Line I
Tacking III
Tacking II
Publication Changes and Tacking
How to Finish
Post Archive
May 2024(0)
May 2024(2)
March 2024(1)
February 2024(1)
May 2023(1)
September 2023(1)
September 2023(0)
May 2023(0)
January 2023(1)
April 2022(1)
December 2021(1)
October 2021(1)
August 2021(2)
March/April 2021(1)
January/February 2021(1)
December 2020(1)
November 2020(1)
September 2020(1)
July 2020(1)
June 2020(1)
May 2020(1)
March/April 2020(1)
January/February 2020(1)
November/December 2019(1)
September/October 2019(1)
July/August 2019(1)
May/June 2019(1)
March/April 2019(1)
January/February 2019(1)
November/December 2018(1)
September/October 2018(1)
July/August 2018(1)
May/June 2018(1)
March/April 2018(1)
January/February 2018(1)
November/December 2017(1)
October 2017(1)
September 2017(1)
August 2017(1)
July 2017(1)
June 2017(1)
May 2017(1)
April 2017(1)
March 2017(1)
January/February 2017(1)
December 2016(1)
November 2016(1)
October 2016(1)
September 2016(1)
August 2016(1)
July 2016(1)
June 2016(1)
May 2016(1)
April 2016(1)
March 2016(1)
January/February 2016(1)
December 2015(1)
November 2015(1)
October 2015(1)
September 2015(1)
August 2015(1)
July 2015(1)
June 2015(1)
May 2015(1)
April 2015(1)
March 2015(1)
January 2015(1)
December 2014(1)
November 2014(1)
October 2014(1)
September 2014(1)
August 2014(1)
July 2014(1)
June 2014(1)
May 2014(1)
April 2014(1)
March 2014(1)
January 2014(1)
December 2013(1)
November 2013(1)
October 2013(1)
September 2013(1)
August 2013(1)
July 2013(1)
June 2013(1)
May 2013(1)
April 2013(1)
March 2013(1)
January 2013(1)
December 2012(1)
November 2012(1)
October 2012(1)
September 2012(1)
August 2012(1)
July 2012(1)
June 2012(1)
May 2012(1)
April 2012(1)
March 2012(1)
February 2012(1)
January 2012(1)
December 2011(1)
November 2011(1)
October 2011(1)
September 2011(1)
August 2011(1)
July 2011(1)
June 2011(1)
May 2011(1)
April 2011(1)
March 2011(1)
February 2011(1)
January 2011(1)
November 2010(1)
October 2010(1)
September 2010(1)
August 2010(1)
July 2010(1)
June 2010(1)
May 2010(1)
April 2010(1)
March 2010(1)
February 2010(1)
January 2010(1)