there's no place around the hack which you may be able to get Chimchar.., nor Turtwig. The only starter D/P PKMN available in the wild is Piplup, which will be removed in the next beta. ;)
after the submarine-thing.., head South from Cinnabar Isle and use Dive and continue the quest. After that, face Entei again and get ready for another legendary battle. ;)
LJ, no, I can't... Only Shadow Lugia and Baby Lugia will be the only fake-legendary PKMN's are gonna be in the hack. ;)