There are many stories to tell about the seas of the seas of Equestria, and to many haven't been told.

Some of them involve pirates.

Some of them involve seaponies.

One probably has pirate seaponies or seaponies fighting pirates, but that isn't this story.

There's also one about a underwater city that's infested with mutated ponies, but that one isn't a Fallout fic and it's better than this one anyway.

But, never the less, here's the only one you will probably hear about a whale.