Twenty-one miles seem abstract when you stand at Shakespeare Beach in Dover and watch the grey-green water stretch toward an unseen horizon. The English Channel appears almost absurdly narrow on a map. It’s completely different in the water.
The shortest route is 18.2 nautical miles from the cliffs close to Dover to Cap Gris-Nez on the French coast. When you convert that to land miles, you arrive at about 21. Nowadays, the majority of swimsuits begin at Samphire Hoe, a restored coastal park sandwiched between Dover and Folkestone. They aim directly for the French headland that protrudes halfway between Calais and Boulogne. It’s a clean shot in theory. In reality, very few people swim 21 miles. That is taken care of by the tides.
The tidal current in the Channel runs perpendicular to any swimmer‘s direction of travel, which is something that is often overlooked in the headline figures. The water pushes you up the Channel for about six hours. After that, the tide turns around you are pulled back down for the next six hours.
If a swimmer is able to cross in 12 hours, they may cover significantly more ground than those 21 straight-line miles indicate by tracing an S-curve through the water. Because of the particularly harsh conditions that day, it was estimated that Henry Sullivan, the first American to complete the crossing back in 1923, swam closer to 56 miles. It’s nearly impossible to believe that figure. Nearly.
The seasoned pilots who accompany each lawful solo attempt have become much more adept at spotting these trends. Before the swimmer even enters the water, a pilot can simulate likely swim trajectories using modern electronics and computerized plotting.
Ideal start times are determined by taking into account the swimmer’s pace, wind speed tide strength. Because they lessen the likelihood of being completely swept past Cap Gris-Nez, neap tides when the moon’s pull is weaker have historically been favored. It could be a much longer swim if you miss that headland.
The precise number of people who truly value what 21 miles in the Channel requires is still unknown. During the main season, which is roughly July through September, the water’s temperature ranges from 57 to 64 degrees Fahrenheit.
Official solo swims do not include wetsuits. In 21 hours and 45 minutes, Matthew Webb became the first person to cross without artificial buoyancy in 1875. Along the way, he was stung by jellyfish. By the way, nothing has changed about the jellyfish. Even now, swimsuits are still stung. It’s practically a given.
Elite open-water swimsuits can complete a swim in as little as seven hours, while determined non-elites who must persevere through difficult conditions may need more than 27 hours. Gertrude Ederle’s 1926 crossing in 14 hours and 39 minutes broke all previous men’s records by almost two hours, shattering preconceived notions about what women could accomplish in open water. She began on the French side at Cap Gris-Nez, which is still the less popular route. Crossings from France to England are currently less common and require permissions from the French government, which have proven challenging to secure.
The governing associations and coastguards from both sides of the Channel came to the decision to formally limit the swim season between April 1st and October 31st. That decision was motivated by safety. Outside of that window, there are risks that the support infrastructure is just not prepared to handle.
The truthful response to the question of how far it is? On paper, it is twenty-one miles. In actuality, it’s whatever the tides make of you.