Craft Abyssal Weapons
To craft Abyssal weapons – you are going to need chitin – a lot of chitin. To get crafting the abyssal gear, you will need fine wood, leather scraps, and the aforementioned chitin. Sounds easy, but there is a catch. To get the chitin, you will need to harvest it from the back of an ancient sea turtle. Yes, you read that right.
The next step is to find one of the giant sea turtles. You can find them floating about in the vast ocean, and once you find one – you should make a note on your map so you can easily return to it in the future. Once you have found one, take your boat up to it, but leave the ladder facing the turtle because you want to easily access your boat – especially if the turtle sinks…
You should that every time you mine some chitin there is a 25% chance that the turtle will sink. If / when the giant tortoise goes under, head back to your boat before it is too late. Also, it is best to mine the trutles with a group of people, as you can get more chitin quickly. Try to start mining at the same time.
The harpoon is a unique weapon that tethers you to other enemies or players after you throw it at them, so it can be used for relocating creatures such as boar into a pen, or commonly for dragging Sea Serpents to land to strand them and make their Serpent scales recoverable (since they normally sink in deep water).
Leviathans are giant sea turtles that will start to sink underwater once you start mining them, so it can be rather difficult to collect enough Chitin to craft these weapons. Using Chitin you can craft both the Abyssal weapons at any level 2 Workbench.