Hi i was wondering does any one know easy ways to get lots of rupees

No DONT use the SALVAGE ARM (not grappling hook thats the thing you use on land) on random parts of the ocean cause there wont be anything there. You only use the salvage arm on red Xs on the sea chart. My advice: if you can go there, go to isle of ruins and explore around. that place used to be a kingdom and theres TONS of rupees lying around (once the water is down). Sometimes, in some secret caves there is a whole PILE of rupees just sitting there waiting for you to get them. Just be careful of a certain cave that has hundreds of rupoors inside a room before the room with tons of rupees.

Also, go to the north east sea chart (4th) and enter the north west one from the top right. Youll be on a part of sea with no purpose behind Bannan Island. Keep sailing around, the plant enemies come, cannon them to normally get 20 rupees, no other enemies, plus when the jellyfish comes, keep cannoning it to get 1 rupee each time. Can be boring but its a great way.

*Incase you dont know, the jellyfish leaps up randomly while you are sailing, hit it to get 1 rupee each time. But be quick because it will make its way below the surface where you cant reach it, each time you hit it it will fly upwards.*

Digging, particularly in marked spots (when the ground looks cracked); I've even found treasure maps. I've only completed 2 temples so far, and I have more than 2000 rupees, and that's after spending about 2500.

Play the Goron game u get treasures and they can be sold and the guy by Bannan island in the ship

Hope i helped