This is two of three ideas I have based on scenes from My Little Pony: The Movie (2017). The third one will take a long while to get to.
 
During the movie when the Mane 6 escaped and Tempest Shadow destroyed the pirate airship, it had me thinking, why didn’t Tempest search the ocean for Twilight and her friends? She did hear them escape and maybe she didn’t see them sail away in an hot air balloon Twilight made with her friends in it. (Well, actually, the Mane 6 almost hit a river in the movie than an ocean, but they could’ve been taken to the ocean by the river, as my thinking.)
 
So I made a deleted scene for the movie, in which Tempest, after removing her armor, dives in the ocean with a re-breather to find the Mane 6. Of course, she couldn’t find them, as they were in Seaquestria, which is hidden away under Mount Arias, and she returns to her ship.
 
(Note: the surface of the ocean was pretty tricky to do, as I wanted to have it blend with the blue of the water, but I did my best.)
 
Originally drawn in pencil. Colors, filters, bubbles, and edits done in Photoshop.