You can get the Salvage Arm from the man who sold you the Canon on Canon Island in the Southwestern sea chart region.
You should get a letter Eddo and he will tell you to go to him to get a salvage arm
You use the salvage arm.
you go to molida island.
You can`t obtain the no excisting item, but you can use the salvage arm.
get a salvage arm from eddo and go 2 the place with the sacred crest
X marks the spot, then use your salvage arm.
Finding treasure underwater. It's a huge pain to use but you get the hang of it after a while.
To get the salvage arm you need to get where the sun sign tells you to close the ds together and when you start to go to the boat the mailbox will be 'dancing'. See what you got and it will be Eddo and he will tell you that he has finished the salvage arm.
get a salvage arm and go get the sun key then go to molida island and dig in front of a palm tree
You get the salvage arm at a certain point in the game. You get it from the guy who gave you the cannon
There is no under water land, but there is the sun key in a box on the sea floor. You have to get the Salvage arm and get the box.