Use a waterproof case, or waterproof video recording device. Attach the suction cups to glass/smooth tiles in the pool, or use the open hooking end with a rope or string. Get creative and you can get any amazing shot you can dream up.
"It's spring fever. That is what the name of it is. And when you've got it, you want - oh, you don't quite know what it is you do want, but it just fairly makes your heart ache, you want it so!" ~Mark Twain