Swim Fins
Swim Fins Level 0
Price 5 gp
Bulk L
Usage worn shoes
These flippers attach to your feet like tight shoes - donning or removing them requires three Interact actions. While worn, you gain a +5-foot item bonus to the distance you move when rolling Athletics to Swim, not when using a swim Speed, and you take a -10-foot item penalty to your Speed.
Source Lost Omens World Guide pg. 69