Had a similar basking shark encounter off the west coast of the IoM quite close inshore just south of Peel sometime in the 90's. It was amazing with similar numbers that you report, difficult to make an accurate judgement but there must have been >100. Had to carefully zigzag through them - do not know what would have happened had it been dark as they did not seem to make any effort to move out of our way.[/quote]
At one point, when we were leaving, having weighed anchor and motoring NE, we touched one that swam across the bow. I think the bow touched the torso, not the tail, but there was an almighty splash and the beast thrashed and sounded so violently that I would not have believed it to be the same animal. It moved from being the lazy looking, dozy, sloth-like behemoth to an angry huge white pointer, and speed changed from idling to incredibly fast in no time. I'm not sure if it was imagination or real, but it seemed as if the normally floppy dorsal fin became erect and stiff.
"Contender" Rival 32: Roseneath in winter, Mooring off Gourock in summer.