You find it in the team aqua hideout.
You trade with Ruby Saphire or Emerald.
You find HM08 Waterfall on BF4 of the Cave of Origin
You have to beat the Dewford Gym then go in the museum in Slateport where there was a long line of Team Aqua, he's on the second floor.
There is no secret or hidden trick to finding Latias or Latios. Well you can use a Action Replay or a Game Shark but I'm talking about not cheating. You find him randomly. I was playing Saphire trying to Find the Regi Pokemon while I was surfing, and i got into a wild Pokemon battle with Latias without even trying to find him. So the best way to find him is to not try to find him.
In the port at Slateport City.
In the Cave of Origin.
you have to find all the ompa lompas
he is in the museum upstairs you should heal your Pokemon because you have to face two magma grunts once you talk to him.
Migrate it from Emerald, Ruby , Saphire
You can find the HM Fly on Route 119.
You must trade it from Emerald.
You find it in the team aqua hideout.
I think its the same place you find him in Ruby and Saphire
migrate from ruby,saphire, or emerald.
He's on Slateport City's museum, second floor.
Jon Saphire's birth name is Jonathan Saphire.