Valentine's Day is about spending quality time with that special someone who floats your boat. And what better way to show your love is deeper than the ocean than by treating your sweetheart to a romantic sea-themed excursion?

But if you thought watching sunsets over water was going to cut it, think again. From staying on the Beatles' famous yellow submarine in Liverpool to pearl diving in the Persian Gulf, CNN takes a look at the top seven dates for adventurous aquatic-lovers.

All you need is love on a yellow submarine

The Beatles may have sung "You can't buy me love," but that doesn't mean you can't buy a romantic getaway on the Fab Four's yellow submarine.

Inspired by the submarine that featured in the band's 1968 animated film of the same name, the floating hotel is moored in the pop idols' hometown of Liverpool.

The converted narrowboat features a psychedelic lounge adorned with gold Beatles records and the original mod scooter from the 1979 British rock film "Quadrophenia."

Film buffs will have extra reason to twist and shout -- the narrowboat also featured in the 1990 Sean Connery thriller "The Hunt for Red October," before its current reincarnation.

Chocolate-making cruise

From the time of the ancient Aztecs, chocolate has been sending us into raptures of aphrodisiac bliss.

But the process of cooking sweet treats can be just as sensual as eating them -- particularly when you're puttering down the Thames in a vintage 1960's boat.

Alan Whatley, former chef at London's prestigious Savoy restaurant, shows guests the fine art of creating sumptuous chocolate desserts -- all while meandering through the south England countryside on a 12 meter wooden vessel.

Setting sail from Henley-on-Thames, the picturesque three-hour journey offers views quite literally fit for a Queen -- Her Majesty's official home, Windsor Castle, backs on to the river.

"It's something a bit different from your standard chocolate in a box," charter manager, Daisy O'Halloran said. "You can learn a new skill but you've also got the romance of the river."

Persian Gulf pearl diving

For hundreds of years, the Persian Gulf has been a rich source of the world's pearls, with divers plunging up to 40 meters below the water to get their hands on the "jewels of the sea."

Now adventurous couples can also try their luck, with Bahrain's Al Dar Island offering day trips on traditional wooden sailboats, called dhows.

After an onboard history lesson and demonstration, guests use a weighted rope to navigate down to the shallow seabed in search of riches.

Once back on deck, they can admire their haul over a lunch of freshly prepared middle eastern dishes.

Lighthouse love-in

"Love has no age, no limit, no death," said 1932 Nobel Prize winning English writer, John Galsworthy.

If you want to show your love is forever, the thousand-year-long musical piece playing from London's only lighthouse comes pretty close.

Lovebirds can take in glittering views of the city from the lighthouse on the Thames, while listening to a unique composition of ancient Tibetan singing bells.

The haunting music, played from loudspeakers, began in 1999 and aims to continue without repetition until 2999.

"It's incredibly romantic," said administrator, Victoria Burns. "You can daydream together whilst enjoying magnificent views of the City through diamond-leaded windows."

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