The Londonist alerts us to the news that the journalist Matthew Parris came to an embarrassing, but thankfully not tragic, end to his attempt to swim the Thames at Rotherhithe (we quite like the tunnel there).  As the Londonist reports:

But the normally level-headed correspondent mixed up his tide tables and, slipping into the water before high-tide, ended up three-quarters of a mile upriver.

The Port Authority of London was apparently not impressed.

Nonetheless, we like his pluck, and call to mind an earlier visitor to London's fondness for watery expeditions.  When Benjamin Franklin found himself in London as a young man, he took to swimming (at least according to his rather puffed-up pages of his Autobiography) like a fish to water:

At Watts's printing-house I contracted an acquaintance with an ingenious young man, one Wygate, who, having wealthy relations, had been better educated than most printers; was a tolerable Latinist, spoke French, and lov'd reading. I taught him and a friend of his to swim at twice going into the river, and they soon became good swimmers. They introduc'd me to some gentlemen from the country, who went to Chelsea by water to see the College and Don Saltero's curiosities. In our return, at the request of the company, whose curiosity Wygate had excited, I stripped and leaped into the river, and swam from near Chelsea to Blackfryar's, performing on the way many feats of activity, both upon and under water, that surpris'd and pleas'd those to whom they were novelties.

Before returning to Philadelphia, a gentleman apparently heard of Franklin's aquatic abilities and asked him to remain in London to teach his sons how to swim. Ben, however, had to return (no doubt to invent something), and the Franklin School of Swimming remained unopened, and alas, unable to assist future natatory journalists.

[M.S.]

Postscript: the cause of Parris's trouble was a muddle between GMT and BST in the tide tables; as ever, Franklin was here first, and came to London with recommendations for a more sensible daylight saving plan (and continued to promote his plan in Paris in 1784).