October 2017 - What to watch for when you are going leeward

placeholder image

October 2017 - What to watch for when you are going leeward

Last month, I looked at two boats going downwind towards the leeward mark. This month, we will discuss the interaction between upwind and downwind boats.

In the diagram, we start with two boats, White and Blue, sailing downwind. Blue is on starboard tack while White is on port tack. They are paying attention to each other and not looking to their respective leeward sides, where two other boats are approaching, sailing upwind. Green is on starboard tack and Red is on port tack.
 
First, we will look at Blue and Green. Both boats are on starboard tack. It may not be obvious at first, but until they pass each other, Green is to leeward of Blue. The definition of windward and leeward says “When two boats on the same tack overlap, the one on the leeward side of the other is the leeward boat. The other is the windward boat.” If we look at the expansion of the boats at position 3, we can see that Green is on Blue’s leeward side. This makes Green the leeward boat and Blue the windward boat. Rule 11 says that Blue must keep clear of Green. If Blue had noticed Green earlier, it is possible that there is another way around. As it is, when Blue notices, the only way to keep clear is to gybe.

A very similar situation exists between Red and White. Red is the leeward boat but here, White is just a bit further ahead and is able to cross Red. At position 4, Red is now to windward of White. There is a transition where Red goes from being leeward boat and right-of-way to being windward boat and give way. It is not clear exactly where that position is – but there is some elasticity in the rules. At the time the transition happens, White is subject to rule 15. Rule 15 requires her initially to give Red room to keep clear. By that time that “initially” has passed, the boats have passed as well.
 
It is simplest to think that whenever it matters, the boat going to windward has right-of-way over the boat on the same tack going to leeward. That is not actually the rule but it is a simple summary of the effect of the rule. I carefully said that this applies to boats on the same tack. Boats on starboard tack, even those going downwind, have right-of-way over boats on port tack, even those going upwind.
 
When you are going downwind, please remember – watch out for the boats coming upwind. If you are on starboard tack going downwind, like Blue before her gybe – watch out for starboard tack boats going upwind. If you are on port tack, like White, watch out for upwind boats on both tacks. A timely gybe or a slight luff to pass ahead is much faster and safer than a last-minute panic.
 
As an historical side note, this rule reverses what our predecessors knew. At one point, boats with spinnakers up had right of way over boats going upwind. I think that had all disappeared before the Second World War so we really shouldn’t be confused today.
 


Leeward and Windward A boat’s leeward side is the side that is or, when she is head to wind, was away from the wind. However, when sailing by the lee or directly downwind, her leeward side is the side on which her mainsail lies. The other side is her windward side. When two boats on the same tack overlap, the one on the leeward side of the other is the leeward boat. The other is the windward boat.
 
11    ON THE SAME TACK, OVERLAPPED
When boats are on the same tack and overlapped, a windward boat shall keep clear of a leeward boat.
 
15    ACQUIRING RIGHT OF WAY
When a boat acquires right of way, she shall
initially give the other boat room to keep clear,
unless she acquires right of way because of the
other boat’s actions.

 

© Copyright 2017 Andrew Alberti
 
 
Posted: 4/29/2019 11:10:41 AM by Andrew Alberti | with 0 comments


Trackback URL: https://rcyc.ca/trackback/140c0f58-b130-4a29-b5a6-14830d76cfe4/October_2017_-_What_to_watch_for_when_you_are_going_leeward.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 sailing.org.
ABOUT ANDREW ALBERTI
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. 

QUESTIONS & ANSWERS
Send your questions to Andrew at kyrules@alberti.ca.

 

ABOUT RCYC: 
166 Years of Tradition | World-Class Sailing | Toronto Island & City Clubhouse
 
Penalties – When and How to Take Them
New Rule Changes III
Mark Room at a Gybe Mark
March/April 2021 - New Rule Changes II
January/February 2021 - New Rule Changes
Post Archive
October 2021(0)
October 2021(1)
August 2021(2)
May/June 2021(0)
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)
RSS