What to do after the third gym Pokemon LeafGreen?

Answer 1

After the third pokemon gym (with Lt.Surge) you should head east (to the right of your screen) and then south (bottom of your screen) once you reach the docks. Follow the docks down and you will soon come to a boat, the SS.ANNE, of which you received a ticket for from Bill the pokemaniac. Board the ship and I would suggest that you enter every room on board because there are lots of items and trainers to battle for exp. you will meet your rival on board, so it's worth you leveling up a bit. On the ship you will eventually reach the captain. Talk to him to get rid of his seasickness and he will give you the HM, Cut. You can then use this to teach to your pokemon (I would recommend you catch a pokemon that you do not want as cut is not a strong move) and teach it to it. Then head through Digglett's cave and you will come out just before Viridan Forest. Head south, cutting the trees and you can receive a few items and trade with a man in a house (to receive a Mr.Mime) then return to outside the tunnel and head east. Here you can battle many more trainers for exp.