Swimming vs. Tide Surfing around Manhattan

4-minute read
analysis
data • MIMS

It’s well known that Shelley Taylor-Smith holds the record for the fastest swim around Manhattan: 5 hours, 45 minutes, 25 seconds.

What’s not quite as well known is that she achieved this feat on a special “fast tide” - a convergence of maritime conditions in the East, Harlem, and Hudson Rivers that occurs only once or twice a year, if at all.

With the founding of the modern Manhattan Island Marathon Swim race in 1982, and more sophisticated understanding of tide cycles, a string of specially planned solo “record attempt” swims were undertaken in the ’80s and ’90s, all on fast tides. After Diana Nyad‘s 1975 swim in 7 hours, 57 minutes, the record was lowered six times by four different people over the next 20 years:

  • 7:14 - Drury Gallagher in 1982
  • 6:48 - Paul Asmuth in 1983
  • 6:41 - Drury Gallagher in 1983
  • 6:12 - Shelley Taylor-Smith in 1985
  • 5:54 - Kris Rutford in 1992
  • 5:45:25 - Shelley Taylor-Smith in 1995

Her record has stood ever since, despite an assault last year by world-class marathon swimmers Petar Stoychev and Mark Warkentin.

To give a sense of how much the tides matter in these swims, Taylor-Smith’s 5:45:25 works out to a pace of 45.2 seconds/100m (12.1 minutes per mile - almost 5 mph). If you assume a 20 minutes/mile average swimming pace (world-class for marathon distance), that means she derived 40% of her overall speed from the river currents!

All this is by way of saying: There’s a reason nobody ever comes close to 5:45 in the annual race. MIMS is never held on the special “record attempt” tides. Why not? Though I haven’t seen this stated explicitly anywhere, I assume it’s because while the “record attempt” tides may push a fast solo swimmer around Manhattan very quickly, it may not be suitable for getting a group of swimmers (of varying speeds) around Manhattan in a reasonable amount of time. The “MIMS tide,” as I understand it, is actually selected to punish the fastest swimmers with head currents (they arrive at Spuyten Duyvil ahead of the tide change). As a result, the MIMS field tends to compress much more than would a current-neutral swim of similar distance.

So basically, the MIMS race and the special “record attempts” are two entirely separate categories of swims. We all know that 5:45 is the fastest overall swim, but that was on a “record attempt” tide. What are the fastest swims on the regular MIMS tide?

What are the fastest swims in the regular MIMS race, typically held on a slower tide? Over the 29 years of the modern MIMS, the 10 fastest swims are as follows:

  1. Tobie Smith, 1999, 6:32:41
  2. Tammy van Wisse, 1999, 6:51:31
  3. Rob Copeland, 1999, 6:52:49
  4. Susie Maroney, 1990, 7:00:27
  5. Matthew Nance, 1990, 7:04:53
  6. Jim Barber, 1991, 7:06:34
  7. Kris Rutford, 1991, 7:06:44
  8. Matthew Wood, 1990, 7:07:32
  9. Susie Maroney, 1994, 7:08:10
  10. Igor de Souza, 1991, 7:08:20

Interestingly, 9 of the 10 fastest times happened in just 3 years - 1990, 1991, and 1999. The 3 fastest times were all in one year - 1999. Perhaps these years were “stacked” with outstanding swimmers. Another possibility is that these years saw especially favorable conditions (faster currents, smoother water, warmer water, etc.).

One simple method of estimating the effect of conditions is to find the median time in each annual race - and compare each individual to the median of that year. The fastest swims relative to the median would therefore be judged as the “most outstanding” swims. Here are the top 10 swims, compared to the same-year median time:

  1. Shelley Taylor-Smith, 1989, 7:32:34 (84 minutes faster than the median)
  2. Shelley Taylor-Smith, 1998, 7:18:07 (-77 minutes)
  3. Jay Benner, 1998, 7:19:40 (-76 minutes)
  4. Chris Derks, 1998, 7:24:02 (-71 minutes)
  5. Jim Barber, 1989, 7:45:15 (-71 minutes)
  6. Shelley Taylor-Smith, 1988, 7:27:44 (-71 minutes)
  7. Susie Maroney, 1990, 7:00:27 (-70 minutes)
  8. Penny Palfrey, 2007, 8:36:01 (-69 minutes)
  9. David Strasburg, 1989, 7:51:10 (-65 minutes)
  10. Matthew Nance, 1990, 7:04:53 (-65 minutes)

And… there’s Shelley Taylor-Smith again! In fact, 3 of her 5 swims (all 1st place overall finishes) are among the top 10 “most outstanding” swims. In other words, she was demolishing the field.

No matter how you look at it - solo “record attempt” swims or regular MIMS races - Shelley Taylor-Smith is the greatest Manhattan swimmer of all-time. It’s not really even close.

NOTE: Much useful information in this post was gleaned from Capt. Tim Johnson’s wonderful History of Open-Water Marathon Swimming.

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