I'm looking for a book I read as a teen it was about a boy and a girl That were in the ocean and they talked to the animals and they talked to a
Thanks for asking! My first thought is Deep Wizardry by Diane Duane, part of her "So you want to be a wizard?" cycle, and one of my favorite books when I was a teenager. It's got the young wizards Nita and Kit diving deep with a group of whales to complete an ancient ritual protecting the ocean, and one of the key characters is Ed'rashketareshket, the Pale Slayer, one of the coolest Great Whites in fiction this side of Jaws.
There are some other possibilities, too, so if that doesn't sound right message back and we'll keep searching!