You can call upon murky sediments in the water to transform a mist spell underwater.
Benefit: You can apply Murky Spell only to a mist or fog spell that normally doesn’t work underwater, such as cloudkill, fog cloud, mind fog, obscuring mist, or solid fog. When cast underwater, a murky spell clouds the water with sediments, producing roughly the same effects as the normal spell would above water except as follows. Due to the dilution, a murky spell has only one-tenth of the duration of a normal spell (generally 1 minute per level, though mind fog lasts 3 minutes), but this reduction doesn’t affect the duration of secondary effects like mind fog’s mental penalties. Abilities that see through mist and fog can’t see through a murky spell unless they also specifically see through murky water (like the mistsight universal monster rule). Instead of wind, currents can disperse a murky spell; any current with a speed of at least 10 feet disperses a murky spell in 1 round. A murky spell has no effect above the water. A murky spell uses up a slot the same spell level as the spell’s actual level.
Pathfinder Campaign Setting: Aquatic Adventures © 2017, Paizo Inc.; Authors: Amber E. Scott and Mark Seifter.