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Offset Mark set at a Windward Mark

The purpose of an offset mark is to separate boats approaching the windward mark from those who have rounded and are proceeding to sail on the first reach. Placing an offset mark can be a safety measure, as a collision in this situation could be fairly severe.  Offset marks are especially important in a situation where the windward mark is fairly distant from the bank.

In addition, the Offset mark can act as one end of a finishing line in conjunction with the windward mark.

At the National Championships which were held at Champion Lakes in Perth, RSAWA wrote into the SI’s, that the two marks would be set approximately 4 boat lengths apart and they would be treated as one mark. It was stipulated that an overlap established at the 4 boat length zone for the first mark would hold till both boats had left both marks astern. They did not state that a boat could not pass another to leeward – just that the rules relating to mark rounding applied to both marks, as if they were one.

In practice, setting an offset mark 4 boat lengths away from the windward mark, and treating them as a single mark has led to quite a few problems in club racing. Searching the ISAF RRS 2009-2012, the amendments to these rules, the case book, numerous Rules Forums and googleing it, I have not been able to find any mention of rules which apply when one considers the two marks as one.

The ARYA Standard SI’s are silent on the question of offset marks. There are no other SI’s that state that the two marks ought to be treated as one that I can find. (Happy to stand corrected if anyone else can find some!)

The problems which arise are normally when a trailing boat, which did not have an overlap at the zone for the first mark (but establishes an overlap by the time they reach the windward mark) travels faster than a leading boat, which sails wide, and then find that they have poked their nose to leeward and have nowhere to go. The leading boat would be entitled to squeeze the trailing boat into the offset mark. This causes quite a few arguments between skippers.

The other problem experienced is that skippers argue that if they hit both marks, they only have to do one turn, as the marks are considered as being one mark, whereas other skippers argue that they ought to do two turns – one for each hit. There are no clear rules relating to this situation.

A lot of these problems can be solved by simply by placing the offset mark further away from the windward mark, so that the 4 boat length zones of the two marks do not intersect (ie place the marks about 8 to 10 meters apart). In this situation, the mark rounding rules apply to each mark independently.

By trying to treat the two marks as a single mark, there are unnecessary, vague and ill defined “local rules” introduced, which are not written anywhere in the official rules of sailing.