You could make a way to get rescured
Do some events like Shark waves. or pirate invaision
On the subject of pirates, you could make it so that they only start appearing once you have a couple of chests. They come to steal your chests and you have to fend them off. If they were to use, say, a harpoon gun or a fishhook like yours to grab the chests, you could cut the ropes with your spear or the axe. You could protect the chests with walls - actually having a purpose for walls would be nice!