talk to guy reading a boat blueprint in the boat factory
then go back
Capt. Stern is on the top floor of the museum. You can't get in though, because there is a line of Grunts blocking the entrance.So first, you need to go to his Shipyard (still in Slateport) and talk to the guy north of the door. His name is Dock, and he'll tell you to deliver the Goods to Stern.When you go back to the museum, the Grunts are gone.You need $50 to get into the museum.
Go to the museum in Slateport. Talk to the grunts, one of them will give you a TM. Then go upstairs and talk to Capt. Stern. Two grunts will come. Fight them. Then Archie/Maxie will come and make bold claims. Your path will be cleared.
He is in Slateport City.
He's in the museum.
In Slateport city harbour you will see capt. stern being interviewed with a large crowd talk to capt. stern and you will go into the harbour thing and then go to their hideout in lilycove city.
Capt. Stern is not in Pokemon Leaf Green. He is only in Pokemon Ruby, Saphire or Emerald.
You get it in Slateport City, by Capt. Stern. Hope I helped :)
Go to the shipyard, and talk to the guy standing by the table with a map on it. He will tell you Captain Stern isn't there. Leave the shipyard, and go into the museum. Go to the backroom, and talk to the scientist. He is Captain Stern. Team Aqua will come inside, and be prepared for two battles. After you beat them, you can give the parts to Capt. Stern. Hope this helps! :)
Near the SS Tidal in Slateport City.
You go to Slateport and go to the museem and you can find him on the second floor
You first meet Capt. Stern upstairs in the museum, where team Aqua/Magma (I forget which) are originally blocking the doorway.
That's how you get the items in the first place by giving capt stern the scanner.