Raced IM Coz 2X, volunteered 2X, and been 10+ times for diving. Great place to race although Oct. will be hot (Sept is worse). But for an Oly, not much of an issue. I love racing and going there. I know people that have rented bikes, if you go on the Cozumel 70.3 or IM page (if you are on Facebook) someone will hook you up. I know the lady that runs the tri shop on the island and can follow up there if you don't find any leads.