Sea Sack

The Sea Sack is a backpack introduced in the Shipwrecked DLC, used to expand the character's inventory. While it has only 6 inventory slots, it slows the spoilage of perishable items contained within. It requires 5 Seaweeds, 2 Vines, and 1 Shark Gills to craft and an Alchemy Engine to prototype. Sea Sacks function identically to Insulated Packs from Reign of Giants.

The Sack itself cannot be placed in one's inventory or a Chest and only one may be equipped at a time. When an Sea Sack is created, it automatically equips itself in the Chest Slot, if it is available. This item uses the same equipment slot as Armor and Vests, which means wearing one requires sacrificing the benefits of the other.

Although Sea Sack cannot be placed in inventory or in Chests, they can be placed on the ground and used for storage. Any item clicked on an Sea Sack which is on the ground will give the 'Store' option allowing the pack to be filled without equipping it.

Despite slowing the spoilage of food items, the Sea Sack does not completely work the same way as an Ice Box. Unlike the Box, the Sack will not stop the spoilage of Ice and Ice Cubes and will not be able to freeze a Thermal Stone.