The common whelk is the largest sea snail found in UK seas, though you're more likely to find the dry balls of empty whelk egg capsules washed up in strandlines.

A bushy brown seaweed that appears bright blue underwater.

Have you ever seen those worm-like mounds on beaches? Those are a sign of lugworms! The worms themselves are very rarely seen except by fishermen who dig them up for bait.

There are several species of cucumber spider, recognised by their bright green abdomen.

It's easy to see where the snakelocks anemone got its name when you spot its flowing tentacles. But be careful when out rockpooling, those tentacles give a nasty sting!