Sturdy Satchel Level 2
Access Member of the Pathfinder Society.
Price 30 gp
This heavy backpack of alchemically treated cloth layered over a metal mesh protects its contents from water damage and other harmful effects. It holds up to 4 Bulk of items, and the first 2 Bulk contained within the sturdy satchel do not count against your Bulk limits. The bag has Hardness 5 and 20 Hit Points. As long as the bag remains closed and is not Broken, water and other liquids can't seep into it.
Source Pathfinder Society Guide pg. 34