A dog walker has told of his surprise at seeing what appeared to be a large shark swimming in Southampton Water.

David Rogers was walking his Miniature Schnauzer Luna along the shoreline in Hook, near the Solent Breezes Holiday Park, at around midday on Saturday when he spotted a large fin poking out of the water.

The 55-year-old from Warsash initially thought it must be a prank by someone wearing a fake shark fin - but the five-minute encounter led him to believe it was real.

READ MORE: Penguin-like bird spotted on Chessel Bay in Southampton

Referencing the film Jaws, he said: "I just thought: 'I'm going to need a bigger boat!'

"I'm certainly not going skinny dipping anymore, I will tell you that," he joked.

The shark was about 15 to 20 metres away from the shore, David said: "It was just hovering.

"It couldn't have been a dolphin, because they are quite active and the fin was too large."

Daily Echo: David Rogers captured these photos of what appears to be a shark fin in Southampton WaterDavid's partner Vicky was at work when she received the photos he took on his mobile phone.

The 48-year-old estate agent said: "I was like, 'you've got to be kidding, this is a wind up'.

"I was dead jealous; in fact, I'm thinking of going back and walking there myself to see if I can see it."

Daily Echo: David Rogers captured these photos of what appears to be a shark fin in Southampton WaterIntrigued to know what it was, the pair did their own research and spoke with Vicky's father Richard Cannon, 75, who is an avid wildlife photographer.

They have since moved away from David's initial theory that it could be an Orca or a Great White Shark and now believe it could be a Basking Shark.

The second-largest species of fish on the planet, behind the Whale Shark, Basking Sharks measure around 8m in length and can be found in most British waters.

Daily Echo: Something's fishy off the Dorset coast...Despite their intimidating size and huge, gaping, mouths, they pose little risk to humans as they feed on the plankton that they filter out of the water.

David said: "It was right where Southampton Water goes into the Solent, so it must have been there swimming and came a bit closer to shore."

Vicky added: "I'm not a huge fan of the sea because of the things normally swimming in it - but you certainly won't catch me in it now!"