Last minute questions

My wife and I and another couple are leaving next Saturday on the Sea. One of the ships excursions at Cancun sounds good to us but we would rather do it idependantly, by way of cab. The excursion is called Cancun overview. It describes two things I have a question about. One: " Your bus will drop you off at a commercial center in the heart of the hotel zone." Where would I ask a cab to take us to get somewhere near this vauge destination?
Two: Where could we go from there, that would have a public beach that is nice? (I don't mind paying a fee.)

[td]

The hotel zone is the middle of Cancun. Every taxi in the country will know where it is. Ask how much or quanto BEFORE you get in the cab. You may also ask about the downtown shopping area. I'm pretty sure Cancun has a tourism board / counsel & a web site. Try looking there for info on public beaches. I've only ever been to the beach at "my" hotel, but I have never been questioned as I walked through other hotel lobbies to check out their accomodations.

[runner15km]

There is a very good public bus system thats runs up and down the main beach road in Cancun. The cost was very inexpensive, about 50 cents to get on. The center of town you can't miss, there is a large traffic circle here and a shopping mall and the Cancun Convention center. I can think of two beaches on the bay - Playa Las Perlas and Playa Langosta here the waves are calm and good swimming for kids. On the Caribbean side try Playa Ballenas, Gaviota Azul or Chac Mool, all can be reach by public beach or taxi.