At first it seemed a bit complicated for doing things that are already in the game (I think it's important to keep the game mechanics simple) but the farm idea can really be something. Maybe implement a way to move the wreckages and put them togethe…
I think that it's way too powerful with it's reload. It should take longer to deploy lines (more in tune with a single shot spear gun), but no limit on deployed lines. That way it's not a jack of all trades, but you don't have to worry as much when …