One Piece Episode 462

[DarthEnderX]

http://onepiece.wikia.com/wiki/Marines

Goes Fleet Admiral > Admiral > Vice Admiral > Rear Admiral > Commodore > Captain > etc.

I don't think I've ever even seen a Rear Admiral in the series. And honestly Smoker was the first time I'd seen a Commodore.

So...Smoker needs 3 promotions to make Admiral. Hmm, he better start catching them Supernovas.

[Archangel]

I don't think I've ever even seen a Rear Admiral in the series. And honestly Smoker was the first time I'd seen a Commodore.

So far the only people seen in One Piece to have held the rank of Rear Admiral are former Marine and current pirate X. Drake and an unnamed Rear Admiral who was in command of the battleships of Impel Down when they were after the Jailbreak League's battleship.

As for another Commodore, there was this guy from way back when

[Assertn]

X Drake used to be a rear admiral before he became a pirate.