In the “GPS snapshots” I’ve shown in the last couple posts, you can see how far apart each swimmer is (6 of them, anyway) in terms of distance. Four hours into the race, for example, Erica Rose was 455m ahead of Ollie Wilkinson, who was in turn 135m ahead of John Van Wisse.
Another way to model the race is to look at when each swimmer passes a given landmark. This shows how far apart each swimmer is on a different dimension – time. Using the GPS tracks provided by NYC Swim, we can actually calculate “split times” for each swimmer between any landmark we choose. And, using those split times, we can calculate each swimmer’s speed (including current) for each segment.
For the purposes of this study, I chose 11 landmarks – three in the East River (Pier 11, Queensboro Bridge, and the Randall Island footbridge), two in the Harlem (Macombs Dam Bridge and Spuyten Duyvil), and six in the Hudson (GW Bridge, Riverbank Park, 79th St, 34th St, Pier 40, and the finish at South Cove). Hopefully they’re all fairly obvious reference points.…