With due respect, I think your boss is crazy. There are very few tours for which the universal advice on these boards is to not try it on your own, and the Tulum Ruins tour is one of these. There are way, way too many variables at play here and the chances of something getting screwed up are higher than minimal. The
DCL tour is about the fastest you can do a Tulum Ruins visit, also. They take you directly off the ship into a boat (rather than disembarking and walking the length of the pier into Cozumel to find a shuttle to the mainland) and you are off the ship typically before they open the gangways to allow others to go ashore. In addition, the scene as you arrive on the mainland is a bit confusing and pretty chaotic even when you are in a well organized group. I talked with several people I know who lived for a long time in the area around Cancun and the Mayan Riviera and they all advised that I should not try to do this tour on my own from a ship at Cozumel.
