Twelve Thunderbirds showed up Wednesday July 8th, a sunny evening with a steady breeze, to join the joy and exhilaration of one design racing on Port Townsend Bay. Is there more fun to be had in this Victorian seaport arts community of ours than that? I think not. 

Twelve boats results in challenging starting action, plenty of crossing situations, and close mark roundings. In all these situations the racing rules of sailing are our friend, provided we know how to use them. They are designed to facilitate an orderly start, to keep boats safe out on the course, and to prevent collisions when a pack of boats converge on a single point at mark roundings. Knowing the rules allows us to take advantage of our rights, and to consolidate our advantages. Playing by the rules makes for predictable behavior. And predictable behavior helps keep us out of trouble.  

This past week Falcon, Possum, and Dorado had a close encounter at the final leeward mark of the day. Consider Dale Dunning’s race video shown below.  What lessons are to be learned here?  

Here is the situation: Possum, Dorado, and Falcon are approaching a leeward mark on starboard tack. Rule 18.4 does not apply 1) because none of the boats must gybe to clear the mark and 2) because this is a gate-mark.

As the three boats approach the zone on starboard tack they are governed by Rule 11: “When boats are on the same tack and overlapped, a windward boat shall keep clear of a leeward boat.”   They are also governed by Rule 12: “When boats are on the same tack and not overlapped, a boat clear astern shall keep clear of a boat clear ahead.”  The video begins with Possum clear ahead and to leeward, Dorado slightly to windward and astern, and Falcon to windward of Dorado.  Dorado must keep clear of Possum, and Falcon must keep clear of Dorado.

These basic rules continue to apply as the boats enter the zone; Rule 18 (“Mark Room”) creates some additional rights and obligations in the zone, but these added rights and obligations are grafted on top of the basic rules 10-17.

Where is the zone? For Thunderbirds the 3 boat lengths zone is 78 feet, or 26 yards, or a quarter of a football field.  At 5 knots the zone is 9.2 seconds from the mark; at 6 knots the zone is 7.7 seconds from the mark; and at 4 knots it’s 11.5 seconds from the mark.  If you remember nothing else from this article, remember this—nine to five: 5 knots in the zone = 9 seconds!

Using the these calculations it appears Possum may just be entering the zone at around 0:40.  Possum is clear ahead when she enters the zone. She has gained the right to sail straight to the mark without interference.  Both Dorado and Falcon must keep clear of her, no matter what happens.  Rule 18.2(b).

The rules are written to apply between pairs of boats.  In this case Dorado properly steers to keep clear outside of Possum. There are no issues between Dorado and Possum.

Was Falcon overlapped with Dorado? Dorado and Falcon had a disagreement about that as they approached the mark. Falcon believed they had in fact been overlapped with Dorado for some time before reaching the zone; Dorado believed Falcon established an overlap only after entering the zone. At 0:15 of the video it looks like there is overlap.

If Falcon was not (inside) overlapped with Dorado when Dorado reached the zone, Falcon had an obligation to stay clear of both Possum and Dorado.  She should have begun to steer to leeward, anticipating the jam up at the mark, and steer clear of Dorado—just like Dorado did of Possum….  If Falcon was not overlapped at the zone, then Falcon fouled Dorado by failing to keep clear of the leeward boat (Rule 11), and by failing to give Dorado mark room (Rule 18.2(b); and Falcon fouled Possum by failing to give Possum mark room (Rule 18.2(b)) and failing to keep clear of Possum (Rule 11 and Rule 12). Falcon is guilty of a host of horribles. Possum fouled Falcon by pushing off her bow (Rule 14) but is exonerated by Rule 14(b) (more like “her alert crewmember should get an award”—thank you!)

By contrast, if Falcon was (inside) overlapped with Dorado when Dorado reached the zone, Falcon has an uphill fight in the protest room with Possum (who kindly did not protest), but Falcon has a case to make.  Her case is the play-ground rule of “no harm no foul,” which arguably is endorsed by the racing rules of sailing in this case:  Falcon was overlapped with Dorado when they entered the zone. Dorado had an obligation to stay clear of Possum, and Dorado had an obligation to give mark room to Falcon (Rule 18.2(b)).  She must do so even if an overlap is broken inside the zone. Rule 18.2(c)(1).  Mark Room means: “Room for a boat to leave a mark on the required side. Also, (a) room to sail to the mark when her proper course is to sail close to it, and (b) room to round the mark as necessary to sail the course.”

Dorado failed to give mark room to Falcon by closing off the path behind Possum. In the video you can see that Falcon bears off to keep clear of Possum. But Falcon changed course abruptly. By changing course Falcon had an obligation to give Dorado opportunity to keep clear Rule 16.1. So no foul by Dorado. As Falcon finds her path behind Possum’s stern blocked by Dorado, who fails to give mark room to Falcon (failing to give Falcon the space she needs to comply with her obligations under the rules to keep clear of Possum), Falcon attempts to duck into the space opening up between Possum and the mark in order to avoid contact with Dorado.  Falcon acts in a best effort to avoid collision with Dorado, complying with rule 14. So the argument goes. If Falcon had then collided with Possum, she would have committed a foul. Rule 21 would not exonerate Falcon because she never had right of way over Possum.  But Falcon did not collide with Possum. Possum’s agile and heroic crew member pushed off and Possum was exonerated under Rule 14. So no harm no foul!   

What should Falcon have done?

If Dorado is right and Falcon was not overlapped at the zone, the answer is easy: Falcon should have slowed and rounded behind Possum and Dorado.

If Falcon is right and Falcon had an overlap at the zone, it’s trickier. The goal in that case is to round behind Possum, but ahead of Dorado.  Half-way into the zone, see video, Falcon was still well clear astern of Possum and anticipated to follow Possum straight to the mark. However, by one boat length from the mark, Possum had slowed and was no longer rounding clear ahead of Falcon, forcing Falcon to change course to avoid Possum.  The three boats were now stacked out of sequence, with the right of way boat (Possum) sandwiched between Dorado and Falcon. Falcon should have moved to avoid this sandwich and eased outside of Possum, earlier and more gradually:  right after Dorado did so.

Moral of the story, as a give-way boat at a leeward mark, you don’t want to be caught inside of the right of way boat without adequate room to maneuver.  Stay inside of boats that have to give you mark room, make sure you maneuver to be outside of the boat(s) you have to give mark room to.

A sunny day on the Bay and no harm done.  With a little help from our friends on Possum. And a lesson learned.

by Roland Nikles, Falcon 1177