Chichen Itza is about 160 miles west of Cozumel.
There should be some tour companies that would get you there an back on time....I was in Progresso that was a 2 1/2 hour drive from Chichen Itza and made it back in plenty of time. If you can get there, it's wonderful, I've been to most of the Mayan ruins on the Eastern side....and Chichen Itza was the very best....If that doesn't fit into your time frame, Tulum is a wonderful site too...and only a 30 minute or so bus ride....watch as your ship docks in Cozumel..you can see the outline of Tulum on the horizon...it's the only ruin built on the ocean....Happy cruising and ruining....
Tulum is on the main land. It is a 50 minute power ferry ride one way, and then about 45 minutes by bus from the ferry dock. We enjoyed it tremendously, but on RCCL we had 8 hours. We spent almost 2 getting there and 2 back, and really had only 1-1/2 hours there which is not enough. Sounds like you will be port a more reasonable time.
RCCL Nordic Empress 1993
RCCL Nordic Prince 1994
RCCL Explorer 2003, 2005
RCCL Navigator, 2004, 2007
RCCL Mariner 2006
RCCL Liberty 2008
RCCL Adventure 2009 Read and post cruise reviews