I have no idea. I live in Mazatlan and have for about 12 years now. March is wonderful. You want miserable try August. Lots of humidity but livable.
Have a great time where ever you go in Mexico.
There are plenty of shore excursions here. There is the Copola Mountian tour, very quint villages along the way and a great lunch with the best banna/lemon creamed pie in the world
There are 2 ways to the Mazatlan City tour. You can do the Walking Tour of if you don't want to walk there are a couple of companies that offere them. My favorite would be Marlin tours as they have open air trollies and you really do get to see more that way.
All the above tours you can book on the ship or with independent drivers for a much cheaper price.
There is also a tour of the Pacifico Brewery and a Kayaking tour that are only offered thru the ships. Also Golf is available thru the ship. Beautiful course.
More adventure some, there will be many bi-lingual guides that will custom make a ride for you.
I hope this helps. I don't know the prices on any of them except the open air trolly tour and that is $15usd at the terminal.