Thunder Badge - An Electrifying Arrival!

Fly to Olivine City.

Go southeast and enter the harbor building.

Follow the path to the pier and speak with the man in the blue hat to board the S.S. Aqua.

Onboard, go south and find your cabin in the northwestern room.

Rest in your cabin if needed.

Battle the four Trainers in the third, fifth, and seventh rooms.

Go southeast and use the stairs to the lower deck.

Go north and speak with the sailor to find his buddy on the upper floor in the second room.

Defeat the sailor's buddy in battle.

Battle the Trainer in the eastern bedrooms, the western mess hall, and the northwest corner.

Use the stairs in the southwest corner to reach the Captain's room.

Speak with the Captain's missing girl inside.

She will take you back to her grandfather, who will give you a Metal Coat. The Metal Coat boosts Steel moves by 10% and evolves Onix and Scyther when traded while held.

The S.S. Aqua will dock at Vermilion City. Exit the ship by speaking to the person in front of the north doorway.

Leave the harbor and enter Vermilion City. Note that Route 11 and Diglett's Cave are blocked by a sleeping Snorlax, and Route 6 to the north will be visited later.

The Pokémon Center is in the northwestern part of the city.

The Pokémon Fan Club is southwest of the Pokémon Center; speak to the man on the far side to receive a Rare Candy.

The Poké Mart is two buildings east of the Fan Club.

Head to the Pokémon Gym in the southwestern part of the city. The power is out, simplifying the Gym's puzzle.

Battle the Gym Trainers and then proceed to the northern room to challenge Gym Leader Lt. Surge.