November 2010 - Tacking Too Close – At The Mark

placeholder image

November 2010 - Tacking Too Close – At The Mark

In last months article we started to talk about tacking too close. The examples last month were nowhere near the weather mark. This month we will talk about one boat tacking at the weather mark. The first thing to understand is that rule 13 still applies, so if the boat on starboard has to alter course before the tacking boat completes her tack, then the tacking boat has broken the rule. 

There more restrictions on the tacking boat when the tack happens near the weather mark. Those restrictions are found in rule 18.3
After a boat passes head to wind, she shall keep clear of other boats until she is on a close-hauled course. During that time rules 10, 11 and 12 do not apply. If two boats are subject to this rule at the same time, the one on the other’s port side or the one astern shall keep clear.

18.3     Tacking When Approaching a Mark
If two boats were approaching a mark on opposite tacks and one of them changes tack, and as a result is subject to rule 13 in the zone when the other is fetching the mark, rule 18.2 does not thereafter apply. The boat that changed tack
(a)        shall not cause the other boat to sail above close-hauled to avoid her or prevent the other boat from passing the mark on the required side, and
(b)        shall give mark-room if the other boat becomes overlapped inside her.

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

In the diagram, the red boat is set to cross in front of the yellow and green boats. She tries to tack in between the two. At position 4 she has completed her tack and neither boat has had to alter course to avoid her so she has complied with rule 13. Since red has changed tacks and has been subject to rule 13 within the zone, rule 18.3 applies. Yellow ends up establishing an overlap inside red so even though yellow was neither clear ahead of nor overlapped inside red when she got to the zone, she is entitled to mark-room from red. Red has to give her room to sail to the mark and to sail her proper course at the mark. Yellow was right on the lay line but has to pinch up to get around the mark. As long as she can do it without passing head to wind she is “fetching” the mark. Red has to give her room including room to pinch up. In the diagram red does this so she does not break a rule relative to yellow.

Green is a little above the lay line. When red completes her tack she is directly in front of green, but green is sailing faster. Green alters course to sail above red. If there was no mark involved there would be no rule broken here, but green ends up sailing above a close hauled course to avoid hitting red. Red therefore breaks rule 18.3 (a). 

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

In the second diagram the blue boat had overstood the mark. She has to alter course after the red boat tacks but this time her alteration of course is up to close-hauled but not above it. Red has technically not broken a rule. I will however say that red is taking a risk. It is hard to prove that blue was not above close-hauled. Her jib will probably luff since it was trimmed for a slightly lower course. Tacking at the mark is always a risky choice.

© Copyright 2010 Andrew Alberti
Posted: 11/1/2010 2:27:20 PM by Andrew Alberti

Trackback URL:–_At_The_Mark.aspx?culture=en-US

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 2016 are based on the Racing Rules of Sailing 2009-12 or 2013-2016 and have not been updated to reflect the changes that apply as of January 2017 with the publication of the Racing Rules of Sailing 2017-20. 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 a National 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


166 Years of Tradition | World-Class Sailing | Toronto Island & City Clubhouse
June 2020 - An Unusual Start
May 2020 - A Big Collision
March/April 2020 - A Three-Boat Finish
January/February 2020 - An Overview of the Right-of-Way Rules V
November/December 2019 - An Overview of the Right-of-Way Rules IV
Post Archive
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)