Drowning

Drowning is steady damage that keeps arriving for as long as your head stays under water or honey. The tick rate is fixed, so nothing about your build slows it down except accessories that address it directly. Defense will not stretch the timer for you.

It is also not treated as an attack, which has one consequence worth knowing: dodge effects will not save you from it, and neither will anything else that keys off being hit. The only outs are the ones that stop the clock, a pocket of air, a potion, or the right accessory.

Oceans and Bee Hives are the two places you end up under without planning to. The Ocean is the obvious one. The hive is the nastier one, because honey slows your movement to a crawl and a deep pool of it is very hard to climb out of under your own power, so a bad drop into honey is a much longer emergency than the same drop into water.

The typical drowning death is not a long swim gone wrong. It is one fall into a submerged pit with no ledge in reach. Lava will not drown you, it kills you a different way, and Shimmer does not drown you at all.

The Flipper and the Flipper Potion let you swim, and that is the single biggest improvement to underwater survival because it converts a panicked sink into controlled movement. Most drownings are a mobility problem before they are an air problem.

Water Walking Boots and the Water Walking Potion keep you on the surface instead, though you can still drop through deliberately, so treat them as prevention rather than rescue. A grappling hook is the free answer whenever there is anything solid within range. The permanent fix is the Neptune's Shell line or a Gills Potion, after which the mechanic stops applying to you.

NPCs drown too, and house validity does not care about liquid at all. Flood a house and its occupant dies without you laying a finger on them, which is the standard way to move an unwanted resident along and free the room for someone you actually want. Enemies forced underwater die the same way, which makes flooded chambers a workable farm design.

There are two exceptions. The Skeleton Merchant is immune outright. The Nurse is not immune but heals herself faster than the damage arrives, so she will sit in a flooded room indefinitely and ignore you.

A Fish Bowl worn in an equipment slot will drown you on dry land, because the game reads your head as submerged. That is occasionally exactly what you want, since it is a controlled and predictable way to kill a character with no hazard setup involved.

It is worth knowing in the other direction as well. If you equip one as a joke vanity piece and then wander off, you will start losing health for reasons that are not obvious from anything on screen.