And then, when it's gotten a female's attention, it folds up its vibrant fan-like abdomen extension and vigorously waves its legs:

Here's a terrific video showing the mating dance in action (one attempt goes disastrously, another gets a little steamy):
Second, here's the Diving Bell Spider:
Argyroneta aquatica is found in Northern and Central Europe and up to latitude 62°N and northern Asia. It is the only spider that spends its whole life under water. However it breathes air, which it traps in a bubble held by hairs on its abdomen and legs.
Via these sites.
*Previously: Disturbing spider attack.