was their a bahamut in KH1?

[Skyblade]

I think Bahamut was a gummi ship.

Nope.

Gummi Ship blueprints:

Kingdom
Hyperion

Named after characters:
Geppetto
Cid
Leon
Yuffie
Aerith

Named after FF summons (and which game they're from, though I probably haven't gotten all of those yet):
Cactuar (FFVIII)
Chocobo (Lots of FFs)
Cindy (FFX)
Shiva (Lots of FFs)
Sandy (FFX)
Carbuncle (FFVIII and FFTA)
Mindy (FFX)
Siren (FFVIII)
Ifrit (Lots of FFs)
Odin (FFVII and FFVIII)
Diablos (FFVIII)
Typhoon (FFVII)
Alexander (FFVII and FFVIII)
Leviathan (FFVII and FFVIII)
Ramuh (FFVII and FFTA)

Named after enemies (Miscellaneous):
Lamia
Sylph
Goblin
Bomb
Remora
Ahriman
Imp
Stingray
Catoblepas
Adamant
Serpent
Atomos
Golem
Deathguise
Omega

No Bahamut.