Needs review
Source: Dragon Magazine #343

Description: You can swim while heavily laden with a reduced risk of drowning.

Prerequisites: STR 15, Athletic

When using the Swim skill while wearing armor, you only take the normal armor check penalty and encumbrance penalty on your Swim check (see pages 123 and 162 of the Player’s Handbook

Normal

Swim checks are subject to double the normal armor check penalty and encumbrance penalty.