Weapons - how to upgrade

[Node]

Hi divers!

I'm like day 10 in or so, and was wondering a few things about weapons.

1. How do you upgrade them? I can craft them but... so far do you only pick up upgrades from chests? There's no craftable way to upgrade a weapon?

2. How to upgrade melee? I have the lvl 5 or so harpoon but still rocking the crappy pocket knife. All I can ever do is find chests underwater. Would be nice to START with, say, a katana or whatever.

[Jarlim]

1) youll get dialogue during the story where duff will offer to upgrade weapons
2) late game youll get dialogue from dr bacon where knife upgrades will be available on iDiver