Well it appeared from the photos taken that it was a Basking Shark which is not uncommon in British Waters although to be fair less common up this way. These fish tend to prefer areas such as Cornwall and the Scilly Isles, Isle of Man, rich in their main food source – zooplankton.
Now I’ve had the privilege of diving with some of these fish off The Lizard in Cornwall and I’ll tell you what they are BIG! Really BIG! What’s perhaps more scary is that they have the same body form as another more infamous Lamniforme Shark – The Great White.
Whilst you know it’s only a Basking Shark, underwater with their mouth closed they look like a Great White, albeit twice the size, and you do have a ‘what if its not’ moment.
This is when you manoeuvre in a non-obvious way to ensure your diving buddy is between you and the shark. Naturally your diving buddy is doing exactly the same to you! Then the shark opens its mouth and it’s blindingly obvious that you are not going to be the entrée on the a la carte menu.
When you arrive at the surface at the end of the dive you both claim not to have been scared, although later in the pub after a couple of beers both of you admit to ‘pants-ing it!’
Anyway these fish are really beauties and I reckon it’s great to see them off Swanage, even if it’s only for a short period. Despite their size little is known about them so if you see one please report it here http://baskingsharks.wildlifetrusts.org/helpus.php .