Upon starting the game, the player appears at a set of standing stones. These act as the spawn point for the player if they get killed (providing the last save was not performed at a boat, in which case the player will spawn near the boat.) Pieces of The Device must be returned to The Stones. There is only one set of standing stones, which is on the centre island. So if you visit other islands, you'll need to ferry the pieces of The Device back to the centre.
The player can also save their progress at the standing stones. With the exception of boats, The Stones are the only place where a player can save.