There is an Island named Cannon Island between your starting Island and the Isle of Ember. There, run around the entire Island to the workshop. Pay 50 Rupees there, and wabam: You have got the Cannon!
the first cannon in Zelda and the phantom hourglass is eddo's cannon which you can buy for only 20 ruppes
to get a cannon you have to go to cannon island
Cannon island
You get it from Eddo on Cannon Island
After a certain point in the game, you go to Cannon Island. Then you get the cannon
you have to go to the place where you got the cannon.
it's the cannon in eddo's garage in cannon island which is only 20 ruppes
I think the gold cannon is the best, because that's the most rare cannon.
there's ice around the isle go in there and shoot the ice with your cannon
phantom hourglass is released in 2007.
you use it to find beard beards treashure.
Stop by Cannon island and pick up a cannon, then go back to the Temple Of the Ocean King.