Three people thought they saw a whale near Bournemouth pier yesterday, and have already named it Derrick.

They saw a 20-30ft creature swimming for about an hour from the West Cliff past the pier. It then went underwater about 400 yards out from the end of the pier when heavy wind and rain set in at 5.15pm.

All three people who saw the creature believe it was a whale, similar to Gilbert, the female northern bottlenose which washed up dead last month a week after first being sighted.

Derrick Hands, 53, a carpet cleaner, from West Cliff, was walking to the Highcliffe Marriot when he saw the creature around 4.15pm.

“I saw a bow wave and a creature in the water,” he said. “It was substantial. It was going slowly and its back was just breaking the water. I’m absolutely convinced it was a whale.”

Friend Victor Stone, 60, a retired company director also from West Cliff, said: “When Gilbert was here you saw her jumping out of the water, but this one was just going along. All you could see was a black back.

“It was a similar size to Gilbert, about 20ft or more. It was definitely bigger than a dolphin. The wake was about the size you get off a small speedboat.”

Clive Bartlett, 48, a chef from Westbourne, was fishing off the pier and said: “I’ve seen dolphins around fishing boats all my life and it was much bigger. It was probably about 30ft long.

“It was going slowly and every now and again it would come to the surface. You could see black fins.”

Jenny O’Connor, Dorset co-ordinator for British Divers Marine Life Rescue, said: “Without seeing it it’s hard to tell. It could be a basking shark, and we get Minke and Pilot whales in the area. We’ve had dolphins moving between the Isle of Wight and Lyme Bay. I’ll have a look myself.”

The Coastguard last night said it had had no reports.