The creature – around 18 feet long – was seen around 400 yards off Caldey Island by Emily Alexander.
Emily was working aboard the Caldey boat Nemesis, skippered by Graham Waring, and they were crossing to the island on Thursday afternoon, May 25, to collect passengers when they saw the whale.
“Graham spotted its spray first, and then we kept out distance but carried on watching for ten to 15 minutes,” Emily told the Western Telegraph.
“Every time it surfaced we could see a plume of spray.”
Emily, who recently set up a new business, West Coast Surf School, in Manorbier, added: “I really feel like I was one of the lucky ones that day.
“I’ve been working on the Caldey boats for 13 or 14 years, and I’ve seen dolphins, porpoises and even a massive leatherback turtle, but never a whale. It was really great to see.”
Emily’s video was shared on Facebook by the Sea Watch Foundation which described the sighting as ‘exciting’ – but urged sea-goers to give the an imal space.
Posting on Facebook, the organisation said of the creature:”Although initially identified as a pilot whale, the bushy blow and shape of the back and dorsal fin, indicated to us that this is probably a humpback whale.
“Sightings of humpback whales in the UK have increased markedly since the 1980s, and the Celtic Deep is one of three areas where they are spotted on a regular basis.
“They are not as commonly encountered close to shore but the Sea Watch Foundation has several sightings records, including one seen by a fisherman off Cardigan Island, Ceredigion a few years ago.
“While this is an exciting sighting, we ask that people give the animal space and follow the local marine code of conduct.
“However, if you are lucky enough to spot this humpback – or any other whale, dolphin or porpoise – please report it to us either via our website or our Sea Watcher app!
https://www.facebook.com/pembsphoto/videos/113693398398896/”
