Fishing is a skill which all players can learn, after defeating Misty. An Old Rod can be purchased for $5,000
at a Fisherman's house in Vermilion City. While fishing, you will unlock new areas and access to new rods.
Fishing Unlocks:
Lv 1: Old Rod
Lvl 5: Good Rod (Bought in Fuchsia City for $12,000)
Lvl 20: Super Rod (Bought on Route 12 for $35,000) and Turtle Cove
Lvl 25: Cerulean Cave
Lvl 30: Toto Cave
Lvl 40: Dragons Den
A bar will show up. What to do?
There will be a "Hook Icon" that's going to move left and right. You will need to press Space Bar to stop the hook. If the hook lands in the yellow box, you'll hook a Pokemon(see image 1). If the hook lands at the tiny green box, you'll *perfectly* hook the pokemon which will give you more Fishing XP(see image 2).
What's Fishing XP?
Fishing XP is experience to level up your fishing level to unlock higher level Fishing Rods, and unlocks fishing in new areas.