Bartenders celebrated the spring sunshine with a bracing dip in the ocean and a cocktail with a special ingredient – seawater.

Brave passersby volunteered to sample the salty concoction which contained tequila, fresh lime, orange syrup and a shot of Brighton sea.

Professional mixologists Nathaniel Shenton and Joseph Tucker said salt is a natural flavour enhancer, so taking advantage of the abundant resource made perfect sense.

Head bartender Joseph, dressed in Victorian-style shirt, braces and trunks, said: “We love to use natural ingredients and seawater is our biggest natural resource.

“We dished out about 15 cocktails all containing seawater and everyone loved them.

"Margaritas have a salt rim so we thought a little bit of natural salt would really work well.”

The Marine Conservation Society found the four beaches in the Brighton had ‘excellent quality’ seawater in March 2013, and the duo put 10ml in each drink.

Joseph added: “That is an amount that anyone going for a swim is bound to ingest and if that much is not safe, even when quality’ by the Marine Conservation Society, then we really need to ask questions about how we measure what is and what is not safe in our marine environment.”

The mixers work at BYOC (bring your own cocktail), a secret speakeasy-style bar in Meeting House Lane, Brighton. After delivering a dose of sunshine to weather-hardened beachgoers the pair plunged into the sea, flippers and all.

Doctors once extolled the virtues of drinking seawater – Dr Richard Russell, an  18thcenturyphysician from Lewes, being among them.

But the Food Standards Authority say it must be fit for human consumption and not at risk of contamination if it is being used as an ingredient.

According to a study by the American National Academy of Sciences, one litre of seawater can be home to more than 20,000 different species of bacteria.

Dr Russell recommended drinking the seawater near Brighton, saying it had curative properties superior to the water from inland spas. Hewas credited with creating the idea of the “sea side mania of the second half of the eighteenth century”.

The contemporary equivalent is 'thalassotherapy’ although the practice of drinking seawater has largely stopped.