The link between rum and the Navy goes back over 300 years, as Alex Bellotti discovered on a trip to the Roundhouse’s Camden Beach.

Should the grips of hay fever render you allergic to the likes of Hampstead Heath or Primrose Hill this summer, there are few better ways to enjoy the sun than by taking a trip down to the Roundhouse’s Camden Beach.

Replete with deck chairs, beach huts and industrial levels of sand, it even captures that seaside smell through a nautically-attired fish and chip pop-up, but the most intriguing attraction I found upon visiting on Friday was the ‘Rum Shack-a-lack’ in its northerly quarter.

July 31, it turns out, is a big occasion for rum lovers. Known as Black Tot Day, it commemorates the fateful date in 1970 when the British Royal Navy last issued sailors with a daily rum ration (the daily tot).

As Peter Thornton, UK brand manager of Pusser’s Rum – sponsors of the Camden Beach stall and previously the Navy’s official suppliers – explains: “The Royal Navy and rum go back hundreds of years. It was the longest running Navy tradition of over three centuries, until it was stopped in 1970.

“This was a huge thing for the then serving sailors – who did not take kindly to the decision – and it is still commemorated by the new recruits too. Black Tot Day is a very big part of the Royal Navy’s history and a very unique – and true – story for rum too.”

So how did rum become so synonymous with seafarers? The answer appears to lie in the 17th century, after Britain’s newfound love of sugar caused a boom in the Caribbean’s sugar cane industry. Travelling to these shores meant seafaring voyages from England took much longer, so beer and wine no longer lasted the distance without spoiling.

As a result, the Navy began to pick up barrels of raw white rum from plantations. A by-product of the sugar-refining process, the liquid wasn’t legally allowed to be exported back to Britain, but since it attracted pirates, plantation owners were all too happy to let the Navy take it.

Initially, this was problematic. Unaware of suitable measurements, rum rations were issued twice a day to sailors in half pint measures; soon, more sailors were losing their lives by falling from the riggings drunk than they were by fighting in battle.

Over the years, rations were brought down to a more tolerable size, but by December 17 1969, The Admiralty had had enough and declared that “the rum issue is no longer compatible with the high standards of efficiency required” in the modern Navy.

Soon, Black Tot Day came to pass, and sailors went into mourning. Some wore black arm bands; tots were ‘buried at sea’ and even mock funeral processions complete with coffin, drummers and piper commiserated the occasion.

In the years that followed until 1975, the Navy saw the highest voluntary redundancy rate in its entire history. It hardly seems a coincidence, so should you find yourself down at the Roundhouse’s rum-shack, don’t forget to raise a glass to a sailor’s lost first mate.