Boatspeed and windshifts

Glorious sun and a warm Force 2-3 greeted the fleets on Saturday.

Multiple Lasers, one RS400 and one OK Dinghy gathered for the start of race 1. With Windward-Leeward courses it was likely that the singlehanders would come out best. The RS400 prefers triangles and despite solid sailing from the Foleys they could never get clear of the singlehanders on the runs. In the end Sheehy's OK Dinghy came out top in both races. In Race 1 it beat all the Lasers not only on handicap but also head-to-head on the water. In Race 2 Richard Harding led the singlehanders home in his Laser with the OK Dinghy behind by about 20 seconds, but leaving the OK dinghy 18 seconds ahead on corrected time.

[photo Brian Murphy]

Race 1 was primarily a battle of boatspeed. With waves of pressure but little change in wind direction the battle was to exploit every puff and to keep the boat moving through every lull. The fleet got an even start and Keane led up the first beat with Sheehy's OK Dinghy close behind. Dwyer caught up on the run before a slow Fifteen provided some interesting moments at the leeward mark, mixing itself in with the leading groups of several races, including ours and the Mermaids.  

With Foley's RS400 far ahead on the water, the next 3 PY boats escaped the enthusiastic Fifteen and the Mermaids and rounded nose-to-tail. Keane led, Dwyer next and Sheehy's OK Dinghy forced to tack away for clear air.

The second beat was the most interesting of the race. Dwyer fell back just a little while Keane and Sheehy swapped tacks up most of the 2nd beat. Sheehy's OK Dinghy finally got some better luck near the windward mark and got inside a group of Fifteens and Fireballs – and Keane’s Laser – right at the mark.

Then the 2nd run saw Keane and Sheehy split sides and run in parallel about 75 metres apart with Dwyer about 20m behind. With little change for most of the run the OK Dinghy finally got a little puff near the leeward mark to bring it home clear ahead.  1 Sheehy. 2 Keane. 3 Dwyer.

Race 2 was a different affair, with shifts dominating the outcome even more than the changes in windspeed. The race had also been joined by some additional Lasers, with Nesbitt and Harding the most notable new contenders.

[photo Brian Murphy]

There was a big pin bias and the start was pretty tight. The leading Lasers (Keane, Harding) got off well and went right. After a 2nd row start the OK Dinghy had to look around for an escape clause and - having stood up for a better view - saw wind on the left. A quick hike out toward that side was enough to allow the OK to sail back right over the top of the group of Lasers and lead around the windward mark…although it only barely made it before a wave of pressure came in from the right and the Lasers weren’t actually very far behind at the mark.

The Lasers fought hard on the run, with Sheehy still slightly ahead. The OK Dinghy went right after the leeward mark and was horrified to see a repeat of the first beat – with new wind and a 20 degree shift on the left potentially inverting the whole fleet. Richard Harding had seen it coming and was about to take full advantage of it, blasting straight up the beat with good speed. While most of the Lasers stayed on the right, the OK Dinghy bailed out and sailed right back across the course to get to the new wind. 

Harding’s Laser was now just ahead. Harding and Sheehy swapped tacks then worked back across to the right where the wind was filling in again. Having benefited from the left shift these two boats now caught the right shift too and by the windward mark they were hundreds of metres clear of the fleet.  There was only a few metres between them but Harding held the lead all the way to the finish despite Sheehy's best efforts. Keane, Dwyer, Nesbitt and the other Lasers were far back, having been dumped by successive huge shifts. The Foleys actually took 3rd on corrected time in this race, having kept clean lines up the beats. Kudos.

The results for race 1 are here.  Race 2 results here.

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Other than that, it’s fascinating to see how the GPS tracks show the effect of the gusts and lulls, with boats speeding and slowing dramatically.  These videos, showing the same races as above, give the boatspeed and angles of Keane and Sheehy. Loads to learn.