From Pathfinder Battlecry!, which isn't enabled.

Deep Sea Plate

ITEM 8

RARE BULWARK INVESTED MAGICAL

Price 500 gp

Bulk 4

Category heavy

Group plate

AC Bonus +6

Dex Cap +0

Strength +4

Check Penalty −3

Speed Penalty −10 ft.

The interior of this heavy, brass +1 full plate is lined with waterproof fabric, especially covering the seams between plates. When worn, it provides a sealed environment that protects you from drowning as well as allowing you to move more freely while underwater.

Activate—Deep Dive (manipulate)

Frequency once per day

Effect The deep sea plate enables you to breathe underwater and gives you a swim Speed equal to half your land Speed while in depths of 500 feet or less for 1 hour.

Effect: Deep Sea Plate

Pathfinder Battlecry!ORC