Open Water Source analyzed the official times of athletes in various open water swims including the one-mile RCP Tiburon Mile, the 10K Little Red Lighthouse Swim and the Catalina Channel.
As the distances increase, the women get better and better relative to their male colleagues, but at all distances, the comparative differences are small.
In particular, the average time of women in the Catalina Channel is seven minutes faster than the average time for men. What is notable is that the overall records in both directions are held by women (Penny Dean from mainland-to-Catalina in 7:15:55 and Karen Burton from Catalina-to-mainland in 7:37:31).
Because men and women do not swim at the same time during Catalina Channel swims, the analysis also looked at marathon swims where men and women swim together such as the 24-mile Tampa Bay Marathon Swim (years 2000—2010) and the 28.5-mile Manhattan Island Marathon Swim (years 2009 and 2010).
Around the rivers of New York City, the women—on average—reign supreme with an average time of nearly 15 minutes faster (8 hours and 21minutes for the women to 8 hours and 36 minutes for the men).
A ten-year analysis of Tampa Bay results shows an exception to these preliminary findings: the men reached shore first with an average time nearly 23 minutes faster than the women (11:00.9 to 11:23.2).
The presentation of data can always be interpreted in a variety of ways, but it is important to note that the average age of women in the marathon swimming world is younger than the men (33.7 versus 41.5 years in Manhattan Island and 34.5 versus 41.0 in Tampa Bay).