Question 1
Must the string described in the definition Sail the Course, when drawn taut, lie in navigable water only?

Answer 1
No. A boat’s track cannot pass over land or through waters that are not navigable; however, the string that represents that track has a requirement to be ‘drawn taut’. This is a test used to determine whether or not a boat has sailed the course. When the string is drawn taut, or pulled tight, the imaginary string is only influenced, constrained or ‘caught’ by the marks that begin, bound or end each leg of the course established and described by the race committee. Islands, headlands, shallow water or other non-navigable water do not influence, constrain or ‘catch’ the taut string.

Example 1
The course described in the sailing instructions is in a trapezoid layout and the particular course described for a race is:
Start – Mark 1 – Mark 2 – Mark 3 – Finish. Leave rounding marks 1, 2 and 3 to port.

The black line in the diagram represents a boat’s track and the red line represents the taut string described in the definition Sail the Course.

On the first leg, while the track of the boat left gate marks 4S and 4P to starboard, the string, when drawn taut is not influenced by those two gate marks because those marks do not begin, bound or end the first leg of the course and, therefore, they do not have a required side for boats sailing the first leg of the course, from the starting line to Mark 1.

Example 2
The course described in the sailing instructions is around islands and the particular course is described as:
Start – Island 1 – Island 2 – Island 3 – Finish. Leave Islands 1, 2 and 3 to port.

Separately, an exclusion zone was described in the sailing instructions, and a rule in the sailing instructions prohibited boats from entering that zone.

The black line represents the boat’s track, and the red line represents the taut string described in the definition Sail the Course.

A boat may choose, or be compelled due to non-navigable water between Islands 1 and 4, to round both Island 1 and Island 4. Because Island 4 is not a mark that begins, bounds or ends legs 1 or 2, the string is not influenced by Island 4, and when it is drawn taut it touches Island 1, but not Island 4.

The rule that prohibits boats from entering the exclusion zone is a separate rule from the rule that establishes the course. Therefore, ‘the taut string test’ is not used to determine whether or not a boat broke the rule that prohibited her from entering the exclusion zone. That rule permits boats to leave the exclusion zone either to port or to starboard, but they are not permitted to enter it.

It is recommended that race committees establish an exclusion zone in a rule separate from the rule that establishes the course. That will help to make it clear that the ‘taut string’ test is not used to determine whether a boat has complied with the exclusion zone.

Question 2
Would Answer 1 for Example 2 be changed in any way if the exclusion zone were, instead, an exclusion line that boats were prohibited from crossing?

Answer 2
No.

World Sailing 2025