Ships Inventory

It's no secret that you start with a new boat every time you open the game, so don't get attached to the cool stuff you find or spend too much time stocking up.
However, I didn't expect this once I purchased my own ship. Perhaps with items found, but certainly not the ones I purchased. The only thing that didn't disappear was my rowboat.
I'd love to be able to purchase a crate too, as I struggle to find ones that aren't item specific.