Pulling on their scuba gear and flippers at a swimming pool in Brussels, Nicolas Mouchart and his wife Florence are not just going diving - they're going out for dinner.
Lowering themselves to the floor of the pool, an especially deep one built to train scuba divers, they swim to one end where their restaurant awaits, five meters (16 feet) below the surface.
"The Pearl" is a two-meter wide white sphere tethered close to the pool's floor. The diners jettison their weighted belts before swimming underneath and up into the pod that looks like a cross between a lunar landing craft and a giant spaceman's helmet.
Food is served by expert scuba divers who deliver foie gras, lobster salad and champagne in waterproof cases before leaving the diners peering out of the portholes, enjoying the strange tranquillity of eating in an air pocket, completely submerged.
"We are launching a new era of restaurants," said John Beernaerts, who founded the NEMO33 pool in the Belgian capital a decade ago.
The restaurant, where an underwater meal costs 99 euros ($106) per person, took more than a year to build and multiple attempts were needed to perfect the design, mechanics and food delivery system.
"It was a wonderful experience," said Mouchart, 41, his hair still wet after the return swim through the warm - 33 degrees Celsius (91 Fahrenheit) - water to the pool side.
"It was the first time in our life that we ate underwater, which was really fun. It's a unique dinner and we will remember this all our life."