Some of the highlights of "Old Mazatlan" would be: the shoreline along the old downtown area and the cliff divers; the lighthouse at the top of the hill at the harbor entrance; the old opera house which is being renovated (or was in October-it may be finished by now) and the whole artist's colony that has built up around it; and of course the Cathedral and the old marketplace.
We thoroughly enjoyed the Papantla Flyers show at the Aztec Theater. The Flyers are just the finale to a very colorful and entertaining folkloric show. Just be sure to get a seat in the shade.
The Golden Zone, where the Aztec Theater is located, is a large assortment of shops, botiques, restaurants and luxury resorts right on the beach. It is in my opinion the best place for shopping on the Mexican Riviera; it has the best variety of stores and merchandise, and the best prices.
We just went to Mazatlan in Oct 08, We really enjoyed the Papantla Flyers show at the Aztec Theater also. We took the tour thru NCL, it also went to the cathederal and other points of interest. We went in an air conditioned bus and we had disabled people on our bus. You might consider taking the cruiselines tour.
I've never heard anyone say they were there when the divers were not performing. And even with 3 ships in port, there is plenty of room to see them. The more tourists there are, the more money there is to be made, and the more often they dive.
Most itineraries I've seen give you 8-10 hours in Mazatlan, which is ample time to see all the sights, shop and even have a shrimp feast on Stone Island or in the Golden Zone.
It is about 20 minutes to the Golden Zone and Aztec Theater from either the ship or Old Mazatlan. The going rate for one of the open air 3 passenger taxis is $10.00.