I have taken the cargo from the junk yard down to the lake. How do i drop the cargo into the water without having to dive in myself and drop it out of my hands?
Throwing items is a bit of a tricky mechanic to get right but the game does a lot to counter and timing mistakes you might have made.
Equip the item you want to throw in one of your hands. Sam is right handed and he will be able to throw items further with this hand. If you press square Sam will swing with the item in his hand. It can be used to hit enemies if needed. If you let go of R2 when you are mid way through the swing you will let go of the cargo and it will be thrown a good distance. You can use this method to throw cargo into crater lake.