RAPID RESPONSE MATCH RACING CALL 2010/006

Rule 10 On Opposite Tacks
Rule 11 On the Same Tack, Overlapped
Rule 17 On the Same Tack; Proper Course
Definitions Tack, Starboard or Port

Situation 1:

Yellow is a leeward boat subject to rule 17. She is sailing her proper course, which is nearly 140° from the true wind angle. Blue is keeping clear. From position 1 to position 3, Yellow pulls the boom across the centreline to the starboard side of the boat, and almost immediately pulls the boom back across the centreline to the port side of the boat. The force of the pulling action back to the port side causes the mainsail to completely fill in position 2.


Question 1a
Does Yellow change tack in position 2?
 Answer 1a
No. Yellow’s windward side does not change. She never sails by the lee and at no time would her mainsail lie on her starboard side if unrestrained.

Question 1b
Does Yellow gybe between positions 2 and 3?

Answer 1b
Yes. Yellow gybes twice as the foot of her mainsail crosses her centreline twice.

Question 1c
Does rule 17 still apply in position 4?
 Answer 1c
Yes. Yellow does not change tack.

Question 1d
Would the answer be different if the mainsail had never filled in position 2?
Answer 1d
No

Situation 2:

Yellow is a leeward boat subject to rule 17. She is sailing her proper course, which is nearly 180° from the true wind angle. Blue is keeping clear. Yellow bears away and begins to sail by the lee. At position 3, Yellow's crew pulls in the mainsail and it fills on the opposite side without crossing the centreline of the boat. At position 4, Yellow returns to sailing directly downwind and the mainsail continues to lie on her port side.

Question 2a
Does Yellow change tack in position 3?
Answer 2a
Yes. In position 3, Yellow is no longer sailing by the lee and she is not sailing directly downwind. She is therefore on a tack corresponding to her windward side, i.e. port. See the definitions Tack, Starboard or Port; and Leeward and Windward.

Question 2b
Does she gybe between position 2 and 3?
Answer 2b
No. The foot of Yellow’s mainsail never crosses the centreline so she never gybes.

Question 2c
Does rule 17 still apply in position 4?
Answer 2c
No. Although Yellow never gybes, she changes tack twice. Rule 17 ceases to apply if the boats do not remain on the same tack.

Situation 3:

Yellow is a leeward boat subject to rule 17. She is sailing directly downwind on starboard tack. Blue is keeping clear. Yellow then pulls her boom across the centreline to the starboard side of the boat and almost immediately pulls the boom back across the centreline to the port side of the boat. The mainsail does not fill until it is back on the port side of the boat.

Question 3a
Does Yellow change tack?
Answer 3a
If the umpires are satisfied the entire sail has crossed the centreline and would lie on the starboard side without the force of the crew keeping it there, then the boat has changed tacks. The umpires will use the principle of ‘last point of certainty’ when applying the rules about ‘on a tack’. See Call GEN 1.

Question 3b
Does the sail need to fill in order for the boat to change tack?
Answer 3b
No. To decide if the boat has changed tack is not dependant on whether the sail has filled. However, when the sail fills it is more likely that the umpires will be certain that the boat is on the other tack.


Question 3c
Does Yellow gybe?
Answer 3c
Yes. Yellow gybes twice.



I’d better give you the definition to go with this call:

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.

As Umpires we need to establish on the downwind at which angle the boats are sailing. With some practice this should be do-able, we are behind the boats and can fairly accurate judge the angle, although mistakes will be made. Situation 3 answers 3a and 3b were not added by the RR-call panel for nothing.

But for the other boat it will be much harder. In situation 1 the boat gybed but did not change tack and in situation 2 the boat changed tack without gybing!

(*&^$$%(*%*%) That means that the “big flap” behind the mast is no longer a reliable indicator, and the tack must be solely judged on the angle. At least the mainsail has to (be) moved………

My first thought reading this RR MR Call was about something John Stanley said in a Umpire Newsletter a couple of years back:

Most umpires will, at least at times, come into the category of 'rules scientists' but we must be careful to make sure that we remain close to the sailors (our customers) and ensure that we umpire the game that they want to play.

Read his full article: Blogging into the corners.

PS: this RR MR Call was republished on the ISAF Website because the first publication lacked the published - and valid until date.