Would you consider changing the damage type when the target is immune to drown? Virtually all mobs in and on water are immune. You could potentially track mobs to water but you would need to give most a boat as well. As an ability it’s area of usefulness has such a strong double constraint that you could reasonably play 100 hours without any gain, which makes it merely decorative.


Maybe more broadly look at if simply having water breathing should grant immunity to water attacks. I mean air breathers are not immune to air attacks, in fact flying works as a penalty for some air spells. Mechanically someone suspended in water would also struggle when a lot is suddenly displaced.