Captain Tim Johnson provided the background information for the September 10th
record-breaking attempt.
Mark Warkentin (shown on left above), Petar Stoychev (shown on right above), Rondi Davies and Tobey-Anne Saracino will be setting off on September 10th on a record attempt.
95 years previously the first authenticated circumnavigation of Manhattan Island was done by 18-year-old Robert Downing, Jr. in a time of 13 hours and 45 minutes on September 5th, 1915. His record was broken the year later by
Ida Elionsky in 11 hours and 35 minutes.
Ida's record-breaking swim of a woman beating the men was replicated in 1995 when
Shelley Taylor-Smith set the current record of 5 hours and 45 minutes.
In 1927, the record was dropped to 8:56 by 25-year-old Bryon Summers who held the Catalina record at the time (set in April 1927 in 13 hours and 35 minutes). Byron and his navigator established the modern course for the Manhattan Island Marathon Swim by starting at Hell Gate and swimming counter clock-wise around Manhattan in synchronization with the tides.
Dial forward nearly 50 years and
Diana Nyad lowered the record in 1975 to 7:57. 43-year-old Drury Gallagher subsequently lowered the record to 7:12 in 1982 and then established the Manhattan Island Swimming Association to organizae the annual race around Manhattan Island.
Captain Johnson has computed the tides for every record attempt from 1983 to 2007 using an algorithm to model the swim he developed as a student at Empire State College. His algorithm predicted the ultimately fastest circumnavigation to be 5 hours and 30 minutes.
In an interesting side note to marathon swimming history, Captain Johnson developed this 16-kilobyte computer program in BASIC when the swim record was a little over 7 hours. But it took a Hewlett-Packard computer just about as long to calculate the swim simulation itself.
When
International Marathon Swimming Hall of Fame swimmer Paul Asmuth used the algorithm in 1983, he became the first person to swim around Manhattan Island under 7 hours with a time of 6:48 and ushered in the age of computer-assisted marathon swimming.
With Paul swimming and Captain Johnson planning, the computer analysis revealed that the swimmer’s finishing time was dictated by when and where they began their swim in the tide cycle.
Over a period of a few years, the record was lowered again until it stood at 6:12 set by Shelley Taylor in 1985. For six years despite several attempts, no swimmer broke the record although
Karen Farnsworth came very close with a 6:13:05 effort in 1989.
The rivers around Manhattan Island were tricky and knowledge was accumulated over time and with much trial and error. In 1991, Kris Rutford made a record attempt based on Captain Johnson's model and was able to match the computer projections through 66% of the swim, but towards the end, Kris, like the others, fell behind the computer predictions. The problem was that the tide was rated at 2.7 knots for the ebb in the Hudson River, but this tide is so fast it does not tend to occur every year.
Captain Johnson had converted the BASIC algorithm and model to Lotus 1-2-3 and used a portable computer onboard the escort boat to correct for the tidal flow. In the meantime, Kris caught up with the theoretical predictions to become the first person to swim around Manhattan Island under 6 hours with a time of 5:54.
True to her competitive nature, Shelley Taylor immediately asked for the opportunity to respond to Kris' new record. Four years later, Shelley got her chance. Starting at Hell's Gate at 2:40 am, she swam up the Harlem River on the fastest tide of the year. She swam the entire Harlem River in the dark and reached the Battery ahead of Kris' time when she was held up by the Staten Island ferry that was docking at 7 am. Not happy with having to tread water for valuable minutes, Shelley tread water, hydrated and learned that she was at the same place in the same time as Kris was when he set the record. Ever motivated, Shelley took off as soon as the ferry moved out of position and put the hammer down for sprint down the East River. She swam the remaining 7 miles in 1 hour and 29 minutes to break Kris' record by 9 minutes.
Her record of 5 hours and 45 minutes still stands.
But Morty Berger, founder of
NYC Swim has a new model which was first rolled out in 2009 when Liz Fry smashed the reverse circumnavigation record around Manhattan Island in a time of 11 hours and 41 minutes. Morty is predicting that it is possible for all four swimmers to go under 6 hours. The tide predicted for the September 10th record attempt is a comparable 2.7 knot ebb current that pushed both Kris and Shelley to their respective record swims.
Can Petar Stoychev, Mark Warkentin, Rondi Davies and Tobey-Anne Saracino come close to Captain Johnson's theoretical limit of 5 hours and 30 minutes?
We shall see on September 10th, starting at 2 pm when the event will be carried live online. Stay tuned for more details.
Copyright © 2010 by Steven Munatones
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Most recently, there have been several wetsuit-clad marathon swims of note from the Bering Strait to northern California. 
The Daily News of Open Water Swimming often receives emails expressing various viewpoints on the sport of open water swimming. 
Captain Tim Johnson provided the background information for the September 10th record-breaking attempt.
