2009 Boston Light Swim August 8, 2009, 8:00am EDT Boston Harbor, Boston MA Weather and Conditions During Race

The Boston Harbor weather turned suddenly chilly overnight Friday evening before the race, dropping water temperatures several degrees. Just one week before the race, we recorded 64-degree water on our boat along Long Island. Otherwise, the weather was beautiful, with clear skies, relatively low wind, and relatively low wave activity.

At the start, boats lined up generally along a line between the Boston Lighthouse and red navigation buoy #4. The race started at 8:00am and headed southwest towards Geoge's Island. There was relatively low boat activity along the Lowell Island channel, save for one powerboat that veered into the race pack narrowly missing one swimmer. At the start, we had two Coast Guard Auxiliiary vessels that did their best to keep boat traffic away from the boat.

Due in part to the low overnight temperatures on Friday night, the water temperature was cold. We recorded 61.2 degrees at the start. As skies were very sunny, we hoped for solar warming of the water, but got none. As the race progressed, our thermometer dropped to 61.0 degrees, and kept dropping. We recorded a low temperature of 60.8 degrees at one point during the race. About halfway through, the water temperature came back to 61.0 degrees, and maintained that temperature to the finish. Even 3 hours after the finish, we were back out on the water, and recorded water temperatures at 61.0 degrees in the early afternoon.

About 45 minutes into the race, an official Coast Guard red-hulled rigid inflatable vessel joined the group and took position at the head of the pack. Due to its recognizeable color and shape, it was effective in slowing down boat traffic that was approaching the swimmer pack.

Wave activity from passing boats picked up as we passed under the Long Island bridge towards Thompson Island. As it was now 10:00am, there was an increase in boat traffic from the Dorchester Bay area heading out for the day. As we turned the corner at Thompson Island towards the finish, the wind seemed to pick up from the north, blowing swimmers from right-to-left as they approached the finish. This is visible on our race track plotting, even though we tried hard to stay on a GPS course to the finish.