Armor Penalty
Using this skill, a land-based creature can swim, dive. navigate underwater obstacles, and so on.
Check: A successful Swim check allows you to swim one quarter your speed as a move action or half your speed as a full-round action. Roll once per round. If you fail, you make no progress through the water. If you fail by 5 or more, you go underwater.
If you are underwater (from failing a swim check or because you are swimming underwater intentionally), you must hold your breath. You can hold your breath for a number of rounds equal to your Constitution score, but only if you do nothing but take move actions or free actions. If you take an attack action or a full-round action (such as making an attack), the amount of breath you have remaining is reduced by 1 round. (Effectively, a character in combat can hold his breath only half as long as normal.) After that period of time, you must make a Constitution check (DC 10) every round to continue holding your breath. Each round, the DC of the check increases by l. If you fail the check, you begin to drown (see Suffocation and Drowning).
The DC for the Swim check depends on the water:
| Water | DC |
|---|---|
| Calm water | 10 |
| Rough water | 15 |
| Stormy water | 20 |
Each hour that you swim, make a Swim check against DC 20. If you fail, you become fatigued. If you fail a check while fatigued, you become exhausted. If you fail a check while exhausted, you become unconscious. Unconscious characters go underwater and immediately begin to drown.
Try Again?: A new check is allowed the round after a check is failed.
Special: You take a penalty of -1 for every 5 pounds of gear you carry, including armor and weapons.
You can take 10 when making a Swim check, but you can’t take 20.
A character with the Athletic feat gets a +2 bonus on all Swim checks.
Time: A Swim check is either a move action or a full-round action, as described above.