You mean to ferry from Cozumel to Playa Del Carmen and then to Tulum and to return to Cozumel for some beach time before your ship leaves??? <img src="http://www.traveltalkonline.com/forums/images/graemlins/duh.gif" alt="" /> How long are you in port? Unless some other poster knows how to do this, there is no way that would be doable!