pf2e.fyi
From Pathfinder Lost Omens High Seas, which isn't enabled.

Like a Fish in Water

FEAT 4
Archetype Marine Marauder

Water feels like a second skin to you, and you glide through it as quickly as a fish. You gain a swim Speed of 15 feet, and you can hold your breath for twice as long. If you already have a swim Speed, it increases by 5 feet.

Pathfinder Lost Omens High SeasORC