As in any offshore race, on board George Collins' Farr 52 Chessie Racing, we first looked at the weather picture. Weather router Susan Gennett had provided us with maps and a forecast that indicated a large, high-pressure center moving east toward the mid-Atlantic coast of the US. This feature would produce a generous flow of northeasterly breezes across southern Florida, with wind speeds forecast to vary from 13 to 18 knots and directions to range from 010 to 040 degrees true. From the noon starting time until the projected finish the following morning, the weather models suggested that the isobars would push a bit to the south, causing the breeze to shift more to the east while strengthening to the 18 to 23-knot range.
The other important piece of information we received was the size and strength of the Gulf Stream. Jennifer Clark's infrared images suggested the Stream to be about 40 to 50 miles wide in the area east of Ft. Lauderdale, with the maximum current approaching four knots in the western portion of the Stream. This would taper to one knot or less farther east.
With the wind projected to be at 020-030 throughout the afternoon and early evening, we knew we would be in for a long, wet ride hiking out on the rail. Because of the stable weather pattern that was in place, we knew we'd be on the wind or close-reaching on port tack, with the possibility of some spinnaker reaching on the last leg if the wind didn't veer too much. Knowing the wind speed and direction relative to our course helped us anticipate which sails we were likely to use. So we checked that the No. 3 and No. 4 jibs had their battens in, the reefing lines were led in the mainsail, the jib-top reacher was ready, and the reaching spinnaker yarned and packed. We placed blocks on the starboard rail for outboard leads and led short sheets through these blocks in advance, since doing this during the race with the boat rail-down and awash, speeding along at 10 knots, would be a wet and possibly dangerous maneuver. And, although we had countless thousands of ocean racing miles among our crew, a few of us were new to the boat, so we also discussed the mechanics involved in reefing, unreefing, and making headsail changes.
Since the course and wind changed little on the first two legs of the race, the real strategic challenge came as we closed on Great Stirrup Cay. Here the heading changed from about 106 to about 153 degrees, and with the wind at a median direction of 50 degrees, that meant a new true wind angle (TWA) of 103 degrees. Many of us on board had enough racing experience to know intuitively when to replace the jib-top reacher with the fractional asymmetrical spinnaker, but because the polar performance curves for these sails had not been well-established for Chessie, we had to reason through our decision as follows:
In most ocean races, there's usually enough sea room to use the try-it-and-see approach, where you set the spinnaker and give up a few degrees of bearing for the added speed. This is especially true if the wind is expected to lift or lighten over the length of the leg様ighter air from the same direction will allow you to sail at a lower TWA than in a stronger breeze. Our navigator Evan Evans reminded us, however, that for about the next 25 miles, the Berry Islands would be under our lee bow, with no more than a few degrees of deviation possible to keep us off the reefs.
Our strategy worked well, since the breeze didn't veer and strengthen quite as much as forecasted, and we were able to carry the fractional asymmetrical spinnaker up until a few miles of the finish, where the breeze veered quickly to 075, forcing us back to the jib top.
While Chessie's PHRF rating of a negative 63 seconds per mile would not win us any prizes, we were pleased to finish only an hour and a half behind Doug Baker's first-to-finish turbo-sled Magnitude. We were also pleased to learn more about the tradeoffs between sails, angles, distance, and boat speed. And for those of us senior enough to remember past SORCs, this was a much faster ride than the old days!
Current Effect on Heading
With the widespread use of GPS, finding our course over ground (COG) was as easy as pushing a button. However, a power failure may force you to consider the following exercise in trigonometry when crossing a significant current flow like the Gulf Stream.
During the Kalik Cup, the heading to Great Isaac was about 090 degrees and the wind was about 040 degrees at 20 knots. It's interesting to observe how the boat's heading changes with varying boat speeds and current strengths:
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