First, I've never heard of a kangaroo going for a swim in the surf. Until now... and it ended up needing to be saved! Got caught in a rip, and sharks had been seen around the same area, apparently. Anyway, who'd believe this story? Well, here's the news articles, and there's also a video:
Keeping to the new creatures on the beach theme, a Dutch sculptor, Theo Jansen, has come up with "Strandbeests", machines made from plastic tubes and bottles that 'live' on the beach - they can detect when they get near the water or the dry sand, and turn around. The 'creatures' get more and more complex and some look positively dinosaur-like. Have a look at the video on TED.
And how could a beach be compete without a Maleo (Macrocephalon maleo)? It is a rather odd-looking bird which lives only on the island of Sulawesi in Indonesia. Apparently the Maleo now has their own private beach-font reserve, purchased for $12,500. The Wildlife Conservation Society together with a local group - Pelestari Alam Liar dan Satwa (PALS) - used donated funds to ensure that the remaining birds have a safe area to nest.