Last week, international media outlets reported that American Jennifer Figge had become (or claimed to have become) the first woman to “swim the Atlantic” — the BBC story is pretty typical.

According to the initial stories, Figge swam from the Cape Verde Islands to Trinidad (3,380 km direct distance) in 24 days, spending up to 8 hours/day in the water. Since this is a tech blog, I know that you’ve all already started to do the arithmetic, and you’re right. Even in the ideal case (no course deviations, 8 hours/day swimming), she would have had to maintain an average pace of 17.6 km/hr to pull that off. She did have the benefit of swimming with the North Equatorial Current at her back — it’s a weak current, but let’s allow her 0.6 km/hr for it, leaving an average required pace of 17.0 km/hr.

The men’s world record for 50m freestyle (front crawl) swimming is currently 21.8 seconds, or 8.3 km/hr. That includes a huge initial speed-up from the leap off the podium, and even then, the pace the brings the world’s top elite swimmers to absolute exhaustion in only 0.05 km. It also takes place in a calm swimming pool with a swimmer wearing a speedo, rather than against huge ocean swells with the swimmer wearing a wetsuit. Even in the pool, no one could keep up that pace for minutes, much less hours or days.

In fact, it was soon confirmed that Figge swam only about 400 kilometers over those 24 days: an impressive distance for an amateur athlete at any age, much less in her 50s, but not the distance across the Atlantic Ocean.

So I guess that “swimming the Atlantic” does not mean the same as “swimming across the Atlantic.” I’m curious about what it does mean, because there are two other people who became famous for “swimming the Atlantic”:

• Guy Delage claimed to have swum the Atlantic with the assistance of a kickboard, covering 2,100 nautical miles (3,889 kilometers) in 51 days. Even assuming 8 hours/day, that works out to an average pace of 9.5 km/hr.
• Benoît Lecomte claimed to have swum the Atlantic unassisted, covering 3,716 miles (5,980 km) in 72 days, swimming 6–8 hours/day. Even assuming 8 hours every day, that works out to an average pace of 10.4 km/hr.

By contrast, in swimming across Lake Ontario in 1959, Marilyn Bell took 21 hours to cover 52 kilometers direct distance, for an average pace of 2.5 km/hr. People have called even that into question, since with currents and primitive navigation equipment in the support boat, she may have actually had to cover a much greater distance, but at least it doesn’t strain credibility.

(The original title of this posting was “Swimming the Atlantic” vs. grade-four arithmetic, but that seemed to be tempting fate, since I’ve likely made at least one arithmetic error in this posting.)