There you are, happily taking a dip in the sea while on holiday in Cornwall. You're rather enjoying yourself - apart from the fact it's absolutely freezing cold, of course.
That is until you see a fin. Yes, A FIN.
RNLI lifeguards were joined by basking sharks over the bank holiday weekend at Porthcurno beach. The unexpected visitors only feast on plankton and aren't known to attack humans.
But still, that's not to say you wouldn't be totally freaked out if you saw one close to the shore. Or close to you, for that matter.
After all, adult basking sharks can get up to - you might want to brace yourself for this - around 30 feet long. They're the second largest species of shark in the world.
Late May/June is the best time of the year to see the gentle giants. Seriously, it seems like they're popping up all over Cornwall - and some people are very excited about it.
Let's just take a moment to appreciate the way basking sharks swim along on the surface of the water, with their mouths just casually hanging right open (it's to filter the seawater for that plankton they love so much, FYI).
This method of eating crisps is the only thing to compare it to.
Aw, they're kinda cute sharks really...
No, you know what, we take it back - we'd still freak out.