April 2010 - A Basic Rule

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April 2010 - A Basic Rule

I spent a lot of time looking at the finer details of the rules. It seems however that many of the major problems on the water are in situations around the most basic rules. In the past few years I have seen several protests and appeals from collisions where the only rule really involved was on rule 10.
When boats are on opposite tacks, a port-tack boat shall keep clear of a starboard-tack boat.

This is a rule that most people know. What I find however is that many people are concentrating on their own competition and forget about the other fleets on the course. They forget that port-starboard situations develop between boats on different legs.

The first diagram shows three places on the course that often develop these situations. The yellow boat has rounded the weather mark and started down the first reach. She is on starboard. The blue boat is still heading towards the weather mark and is on port.   She has to keep clear.

The Red boat has rounded the gybe mark and gybed onto port. The green boat is early on the weather leg and on starboard. Red has to keep clear.
The black boat is coming to leeward on a direct leeward leg. She is on port tack and must keep clear of white on starboard. All of these are fairly obvious but it easy to forget to watch out for them. Since the boats are sailing towards each other, the closing speed can be pretty high so a collision can be serious.

The next diagram shows a situation where sometimes people forget which tack they are on. All of the boats are sailing directly downwind. All of the boats are on starboard except orange. If orange had her main on the other side she would be right of way (clear ahead) over pink and right of way (leeward) over grey.   It would be worth her while gybing but she has waited too long. Right now if she gybed her boom would probably hit purple.

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

In my final diagram I wanted to show two things. The first is that port starboard situations appear even at highest (or at least highest price) end of the sport. The black boat (USA) is on starboard. The white boat (Alinghi) is on port. This situation happened at the start of the first race of the 33rd America’s Cup. Alinghi got a penalty for not keeping clear. The second thing I am showing is a new diagram drawing program that actually has catamarans. I wanted to try it in honour of our retiring Vice Commodore Fleet and C-Class Catamaran champion Fred Eaton. Unfortunately while the program does have catamarans it does not have trimarans.   Maybe Larry Ellison can offer some programming support to develop one.

© Copyright 2010 Andrew Alberti
Posted: 4/1/2010 3:00:12 PM by Andrew Alberti

Trackback URL: https://rcyc.ca/trackback/606f319c-8941-4e92-a6a6-f3503b125d55/April_2010_-_A_Basic_Rule.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 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 sailing.org.
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 kyrules@alberti.ca.


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