I 'm in the middle of a staring contest with the most serene bouncer I've ever encountered. Her stony gaze is cool, calm, composed. A miracle really, given that I'm clutching a bottle of wine in one hand, a bit of old rope in another and I've lost 50 per cent of my footwear. But then she's seen it all round these parts. From millionaire Alaskan oil drillers to Saint-Tropez party boys, we've all come to have a pop at her precious cargo.
Fifteen metres below sea level in Little Ston bay, a teal-coloured cove in Croatia's lush Pelješac peninsula, sea grass sways hypnotically, silver fish dart in and out of coral, and just past the statuesque female lies the prize – a rust-covered cage, thick with algae, housing neat rows of Roman style amphoras. It's not a forgotten cemetery of pirates' grog but an underwater emporium belonging to local winemaker Ivo Šegović, who is shaking up centuries-old tradition by ditching dusty underground cellars for something a little wetter. It's the first time I've gone out on a wine run wearing scuba gear, that's for sure. Clutching my bounty, I swim slowly upwards, past meandering sea snails and scuttling crabs until I breach the water's surface, brandishing the amphora triumphantly above my head, as though I've just excavated Atlantis. I'm half expecting to feel the angry sting of Neptune's trident at any moment in penance for pillaging his stash, so when icy fingers grip my right foot, I screech, inhale a mouthful of seawater and splutter incoherently until the masked face of dive instructor Sanja looms into sight. She's waggling an errant flipper at me (it must have fallen off during my ascent), her eyes twinkling behind her scuba mask. I guess I'm not Jacques Cousteau quite yet
Hauling myself back into the boat and shrugging off the oxygen canisters, I chat to the man behind this aquatic adventure. "We first started exploring what would happen if we kept our wine underwater back in 2009," says Ivo, director of Edivo Vina winery. "It took another three years to secure all the paperwork and permission."
He goes on to explain, as our boat judders across the bay towards shore, that in order to rent the space on the seabed from the local council, he first had to prove that keeping his wine underwater would not harm the environment. Then there was the no-small matter of finding the perfect spot. "We started off with ten different locations and whittled them down to this one."
The fact that this patch of the bay is teeming with marine life, including the colossal oysters that put the town of Ston on the map, was a huge part of the draw. "When we pulled up the first crate, the amphoras of wine were completely transformed," says Ivo excitedly. "It was like they'd become part of the ocean."
Turning my own amphora over in my hands, I see what he means. Its smooth surface is studded with pearl-coloured oyster shells, blue-grey mussels and delicate pieces of pink coral, all mapped with intricate webs of seaweed and fragments of fishing nets. "We leave each batch of wine down on the seabed for up to two years – some in amphoras, some in glass bottles – and by the time we pull them back up again, there can be up to 3,000 oysters clinging to them. It's like the sea doesn't want to give them back," says Ivo, who endured a steep learning curve of leaky vessels and ruined batches: "It was a fiasco! We lost a lot of money. Everyone told us to give up," – but the determined oenophile, who comes from generations of winemakers and claims to have drunk "at least one glass of wine a day" for his entire life, refused to throw in the towel. 'I just couldn't get my grandfather's voice out of my head. Whenever I'd go down into his wine cellar as a child, he would always say 'Close the door, close the door!'. It was to keep out the light, and that's what gave me the idea to take the wine underwater."
Now each amphora is protected from its briny surrounds by three separate layers of wax seal, and Ivo dives down every couple of weeks to check on his bottles, often accompanied by curious customers who are encouraged to choose their own tipple from the seabed, alongside a qualified dive instructor, as I've just done. Plonking your plonk in the surf might sound like the act of a madman, but there's a surprisingly shrewdness behind it. The water temperature in Little Ston bay remains at a constant 15 degrees all year round, and conditions on the seabed are dark, silent and still, with few waves to disturb the cache. The gentle rolling of the tides massages the wine into what some say is a smoother, more rounded flavour, and this unusual coming of age, combined with the wine's unique presentation – customers keep their amphora after imbibing its contents – means Ivo can charge between €67 and €280 per bottle.
But is it just a clever gimmick, or could underwater ageing be the future of winemaking? Some of Dubrovnik's finest restaurants seem to think so. Back on terra firma in the chic Nautika establishment, with its sweeping views over the old city walls, a white-gloved sommelier carefully uncorks an amphora as he explains: "The pressure of the ocean can actually help to produce a more complex, aromatic wine. Every ten metres of depth subjects the bottle to one further atmosphere of pressure, which changes how the wine reacts inside the bottle. It will take many years of experimenting before we know what that perfect depth is" It's a challenge that Ivo is happy to meet head on. "To begin with, everyone thought I was an idiot. A crazy man. But now people are starting to see the benefits," Ivo says of his underwater wine. Earlier this year, a rival Croatian venture sank 30 bottles of porter beer seven metres underwater in a secret location near the island of Pag. "By the end of 2018, we plan to have submerged around 500 bottles," says Marko Dušević, founder of Coral Wine. "Our belief is that beer changes a lot in the sea, and for the better."
It's not just Croatia that's diving into the trend. Its tentacles stretch further afield, too. Just north of Bilbao, Crusoe Treasure Underwater Cellar ages its wine on an artificial reef, while Napa Valley's Mira winery sunk bottles of its Cabernet Sauvignon to the bottom of Charleston harbour in South Carolina. Ironically, perhaps, this new wine race has a series of ancient tragedies to thank for its emergence, with a spate of shipwreck discoveries, from which intact bottles of wine were retrieved, kickstarting the craze. Among these treasure troves was a 19thcentury shipwreck found in 2010 in the Baltic Sea, with 168 Champagne bottles aboard. When these 170-year-old bottles were fished out, many were still perfectly drinkable, with one even fetching a whopping €15,000 at auction. If a bottle of bubbly was still in peak condition almost two centuries after it was designed to be drunk, surely it pointed towards the exceptional preservation qualities of its environment? Keen to replicate the experiment, Champagne house Veuve Clicquot decided to sink some of its finest fizz near the original wreck site, 40 metres beneath the waves. Since 2014, the team has regularly brought up bottles from the seabed for professional tasters to compare their contents with a set of duplicate bottles ageing in a traditional cellar in Reims, France.
Whether or not the flavour of sea-aged wine is actually better, or simply different, is a hot topic within wine circles. When Jim Dyke Jr, president and sommelier of Napa Valley winery Mira, retrieved his Cabernet Sauvignon from the bottom of Charleston Harbour, he exclaimed: "It's genius! We've turned a 2009 into a 2007 in three months." A series of blind tasting tours around seven cities proved that 99 per cent of people agreed with him that the underwater wine tasted different to its cellar-aged equivalent. However, there are plenty who would argue there is a yawning gulf between ageing 'quickly' and ageing 'gracefully'. "Storing wine under water is certainly novel. But I don't see any real benefit to the flavour to justify the elevated retail price," says Sasha Lusic of independent Dubrovnik wine bar D'Vino. "The wine game can be a cut-throat industry and competition is growing, especially here in Croatia. Smallbatch wineries need to make money first and foremost, and something like this is a good way to bring people through the door." I'm about to find out for myself whether the wine warrants the wetsuit as, having left the elixir to breathe for an hour, we're finally pouring my catch of the day at restaurant Nautika, alongside plates piled high with cured meats and sheep's cheese. Breathing in its heady aroma, the wine smells robust, full-bodied, like plum jam laced with spice and something else. Cinnamon? Cloves? "Exactly!" says Dora Mratović, manager of Edivo Vina. "Dingaĉ and Postup, the two local grapes used in our wines, both derive from the Plavac Mali grape, which is basically the grandfather of Zinfandel."
I take a long glug. It smacks of rich berry-fruits in the mouth – redcurrants, blackcurrants with a lingering sweet finish. It's a big, bold, syrupy grand dame of a wine and, I can already tell, dangerous. Speaking of danger, Ivo tells me that the biggest threat to Croatian wine has always been wild pigs, which can snaffle up more than 10 kilos of grapes per day. The swines. "Now, the biggest threat is inquisitive fish. Maybe the odd shark. Very different to back in my grandfather's day!" he roars with laughter. To his critics, and those who suspect his venture is little more than a savvy marketing ploy, Ivo has this to say: "We tend to think of winemaking as being an age-old tradition, but why not innovate? We have this vast untapped resource all around us – the ocean. Future generations might look back and say 'You used to keep wine in wooden barrels? Underground? Are you crazy?'"
It's a sentiment echoed by the researchers who first stumbled across the 2010 Baltic Sea wreck, who prophesied: "These sleeping Champagne bottles have awoken to tell us a new chapter in the story of winemaking..." In vino veritas. The tide, it seems, is turning. Dive for your wine at Edivo Vina (from €60, May-November),