2003 Boston Light Swim
GPS Plot of Route Swum

This map shows a GPS track of the escort boat for Will Riddell during the race, which very closely approximates Will's position during the swim. At most turns around islands, Will swam somewhat to the inside (and shallow) side of the boat. We had to navigate significantly to the south of George's Island to avoid a construction zone hazard. (All boats and swimmers stayed to the south of the hazard as we did.)

The GPS track indicated a linear distance swum of exactly 8.0 miles. (This is straight surface distance, and does not take into account the effort lost to waves.) Weather during the race presented a westerly wind of 10-15 knots, which provided a fair amount of wind chop that swimmers had to swim into. As the race progressed, there was a large amount of boat traffic chop, especially between the Long Island bridge and the finish. (This is evident between mile 5 and mile 6 in the data below.)

Mile-by-mile analysis of GPS tracking data yields this information:

Race leg Time to complete leg Ground speed for leg
Start - Mile 1 20 minutes 3.0 mph / 2.6 kts
Mile 1 - Mile 2 18:00 3.2 mph / 2.8 kts
Mile 2 - Mile 3 24:00 2.6 mph / 2.3 kts
Mile 3 - Mile 4 22:00 2.7 mph / 2.3 kts
Mile 4 - Mile 5 25:30 2.4 mph / 2.1 kts
Mile 5 - Mile 6 27:30 2.2 mph / 1.9 kts
Mile 6 - Mile 7 24:00 2.6 mph / 2.3 kts
Mile 7 - Mile 8 24:00 2.6 mph / 2.3 kts