A creature with a greater swim speed can move through water at its indicated speed without making Movement checks, even during combat. Greater swim grants a +2 training bonus to Movement skill checks to swim, which must be used when navigating hazards or performing tricky tasks while distracted. Furthermore, while swimming, a creature with a greater swim speed can make a Movement check to perform any actions normally possible with Acrobatics when on land, such as tumbling to avoid attacks of opportunity. Creatures without a swim speed cannot use either Acrobatics or Movement in this fashion while swimming.
- Prone: Creatures with greater swim cannot be made prone, but any time they are subject to the prone condition, they are instead slowed until the end of their next turn, after which it automatically clears (even if they don't move).
- Difficult Terrain: Creatures with greater swim are not normally subject to ground-based difficult terrain, but they are subject to hazards like strong currents and vortexes which constitute difficult terrain in water.
- Permitted Movement: Creatures with greater swim can perform charges, make 5-foot steps, run or withdraw.