Swim
Movement
Part of Movement
Swim is a MovementMovement MovementMovement is how you change your position. you use to MoveMove ActionMove is the Action you use to change your position. through water or another fluid dense enough to propel you. Fights while submerged use Aquatic CombatAquatic Combat CombatAquatic Combat is Special Combat that occurs while submerged..
Core Rule—Swim
Without a Swimming adaptation, each SpaceSpace RuleSpaces are grid tiles that measure position, distance, and Size. you Swim is Difficult TerrainDifficult Terrain MovementDifficult Terrain is any Space that slows your Movement, such as rubble, deep water, or a sheer wall..
Source Player Codex