Their hides provide material for clothing, shelter, and watercraft.

Their bones and sinew provide material for tools and bindings.

The exploitation of marine mammals requires specific technology: harpoons for striking and holding animals that can dive and escape, floats to keep struck animals from sinking, the watercraft needed to pursue animals in open water.

The specific forms of these technologies as used by the early coastal peoples of the Alexander Archipelago are not directly preserved in the On Your Knees Cave record, but their functional necessity is implied by the evidence for marine mammal consumption in the diet.

The sea otter deserves particular mention.