History courtesy of navigator and Captain Tim Johnson, author of the History of Open-Water Marathon Swimming.

The 100th anniversary of the first circumnavigation swim around Manhattan Island will be on September 5th this year.

At the age of 18, Robert Dowling jumped into the rivers around Manhattan Island (Hudson River + East River + Harlem River) and completed the first swim around the heart of New York City in 13 hours 45 minutes, 100 years ago.

While Dowling pioneered the first circumnavigation swim, it was until 1927 until swimmers started to swim counterclockwise around the island in synchronization with the tides. The planning of the swim received a boost in 1983 when Empire State College student Tim Johnson of Port Washington, New York started to compute the tides for every attempt using an algorithm with his computers he had available to him at the time. The algorithm has been continuously improved upon ever since. The current tidal planning is now in the hands of NYC Swim founder Morty Berger.

After graduation, Johnson kept on swimming, documenting history of the sport of marathon swimming and was later inducted in the International Marathon Swimming Hall of Fame. He provides some highlights of the 28.5-mile (48.5 km) swim now called the Manhattan Island Marathon Swim:

The first record of 13 hours and 45 minutes was established by Robert Dowling in 1915. The first woman to swim around Manhattan was Amelia Gade, age 22, on September 26th 1921 in a time of 15 hours 57 minutes.

In 1927, the record was dropped to 8 hours 56 minutes by Bryon Summers. At the age 25, he also held the Catalina Channel record at the time [in 13 hours 35 minutes]. Summers and his navigator established the modern course for the swim starting at Hell Gate and swimming counterclockwise around the island in synchronization with the tides.

On October 6th 1975, Diana Nyad, age 25, lowered the record to 7 hours 57 minutes.

This was followed by Drury Gallagher, age 43, who lowered the record to 7 hours 12 minutes on July 19th 1982. Gallagher also established the Manhattan Island Marathon Swimming organization that year and the annual competitive swims around Manhattan began.

By 1983, the algorithm developed by Captain Tim Johnson predicted an ultimate fastest transit time of 5 hours 30 minutes. The algorithm was developed using a 16 kilobyte computer program in BASIC. At the time, Gallagher’s circumnavigation record was about how long it took his Hewlett-Packard computer to calculate the swim simulation.

When Paul Asmuth of California, the reigning World Professional Marathon Swimming Federation champion, used the algorithm on August 7th 1983, he became the first person to swim around Manhattan is under 7 hours. His swim of 6 hours 48 minutes ushered in the age of computer-assisted swimming.

One important less was revealed by the computer analysis: any given swimmer’s finishing time was dictated by when and where they began their swim in the tide cycle. Later in 1983, Diddo Clark dropped the women’s record to 6 hours 52 minutes while Gallagher lowered it further to 6 hours 43 minutes.

Overa period of a few years, the record was lowered until it stood at 6 hours 12 minutes by Shelley Taylor-Smith of Perth, Australia in 1985. Then the rivers took over. For six years, despite several attempts, no swimmer could break the record, although one swimmer, Karen Farnsworth, did essentially tie the record.

Swimmers learned the lesson that the river flows around Manhattan were eventually revealed purely by accident. In 1991, Kris Rutford of Nebraska made an attempt on the record with Johnson’s assistance. True to form, Rutford matched Johnson’s computer projections through two-thirds of the swim – the Harlem River followed by the Hudson River. But it was in the East River where the swimmers always fell behind the computer predictions that were now converted to Excel using a portable computer.

The tide on the day of Rutford’s attempt was rated at 2.7 knots for the ebb tide in the Hudson River. This tide is so fast that it does not occur every year. The tides led Johnson to launch a series of corrections to the program aboard Rutford’s escort boat as Rutford started to drift wide under the Williamsburg Bridge. When Johnson checked the prediction for passing under the Williamsburg Bridge with Rutford’s actual time the swimmer had gained time back. When he reached the tip of Roosevelt Island, even more time was gained back. Ultimately, Rutford became the first person to swim around Manhattan Island in under 6 hours, completing the swim in 5 hours 54 minutes that broke Taylor-Smith’s record by 18 minutes.

The competitive Australian was on the telephone within 24 hours asking Johnson for an opportunity to respond to Rutford’s record-breaking swim. The next date that put the reigning World Professional Marathon Swimming Federation champion in the same fast current that Rutford benefitted from occurred four years later. She put it to good use as she dropped the record on July 15th 1995.

Under the direction of Captain Johnson, she started her swim at Hell Gate at 2:40 am and headed up the Harlem River on the fastest tide of the year. Taylor-Smith swam the entire Harlem River in the dark as she reached the Battery ahead of Rutford’s time, but was held up at the Battery for 2 minutes by the Staten Island ferry that was docking at 7 am. While she was treading water consuming liquids, Captain Johnson told her that she was in the same place in the same time as Rutford was when he set the existing record. That was all that she had to hear to motivate her as she picked up her stroke down the East River. She swam the 7 miles of the East River up to Hell Gate in 1 hour 29 minutes to break Rutford’s record by 9 minutes and her previous personal record by 27 minutes.

In 1993, Morty Berger took over the Manhattan Island swimming organization from Gallagher and later started its current entity of NYC Swim. NYC Swim has since seen thousands of swimmers take to the waters of Manhattan in a renaissance of open water swimming that has made Manhattan the epicenter of American open water swimming.

Marcia Cleveland dropped the American women’s record of 5 hours 57 minutes in 1996 while Taylor-Smith’s record of 5:45 continued to stand well in the test of time.

Berger predicted in September 10th 2010 that the same 2.7 knot ebb current in the Hudson River could help world marathon swimming champion Petar Stoychev, Olympian Mark Warkentin, Rondi Davies of New York City, and Tobey-Anne Saracino of Rye, New York set new records. The entire record-setting attempt was broadcast over the Internet live, but a late start precluded any record swims on that day.

But Berger continued to plan and recruit top-level swimmers well.

In 2011, 36-year-old Australian Oliver Wilkinson and Rondi Davies were ready to set new standards. The pair pushed each other and Wilkinson set the current record of 5 hours 44 minutes 2 seconds. In the Manhattan Match Race and Record Attempt, 41-year-old Rondi Davies also broke Taylor-Smith’s 1995 record of 5:45:25, finishing in 5 hours 44 minutes 47 seconds. Interestingly, their record swims were just a shade over the record prediction of 5:30 made in 1983. At that pace, swimmers would average 11.5 miles per hour (or an incredible 18.4 km per hour).

Who knows how far the record will ultimately fall in the 21st century?

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