Steven stone lives in mossdeep. go to his house ( the one at the northwestern part of the island) and he will give it to you. BUT you need to beat liza and tate, the city's gym leaders, to use it.
Dive is obtained from defeating Tate and Liza at Mossdeep City's Gym.
Dive is not an HM in firered if you want a Pokemon to learn dive trade it to ruby, sapphire or emerald then take it back after teaching it the move.
Maybe you should see steven in mossdeep city.
You need to know the move dive and get something from underwater
Dive is not an HM available in Leafgreen. If you want to teach a pokemon Dive trade it to any of the Hoenn Region pokemon games (Ruby, Sapphire, Emerald) and use the HM Dive to teach the move and then you can trade it back. NOTE you cannot use Dive outside of battle just like Ruby, Sapphire, Emerald since it's not an HM instead it's a regular move that can be removed either by the Move Deleter or by teaching a different move.
Since dive is not a HM in firered you will have to trade a Pokemon to a friend that has ruby, sapphire or emerald then using that game use the HM Dive to teach the move Dive to that Pokemon trade it back so firered can have that Pokemon again it will still have Dive however you cannot use it to dive underwater.
You can't unless you trade a Pokemon from Pokemon Ruby, Sapphire or Emerald and get a Pokemon that knows Dive. The HM Dive is not necessary in Pokemon Firered and is thus not avaliable. However, a Pokemon that knows Dive can be traded from Pokemon Sapphire, Ruby or Emerald version to Firered.can notI can't remember much, but I think you have to get it from Wallace or Juan.
simply press 'B' or go to pokémon list > *pokemon with 'dive' > DIVE
Steaven gives it to you at mossdeep city, go to his house after you beat the gym and he will give it to you.
No, it is only available in Pokemon Ruby, Sapphire, Emerald, Black, and White. As just a move, yes, you can keep leveling up for Dive. It is mostly from Water type Pokemon.
sorry NO. but you have to dive
it isn't in Pokemon platinum its in ruby and Sapphire