By Plane. The airlines use the Rafael Buelna airport, located mile and a half from the city.
 

By Bus. There is a really modern and comfortable bus service to travel to Mazatlan, including TUFESA and TAP.

Driving. You can use freeway 15 or International Highway if you're coming from the North or the South. You can use "La Costera" Highway if you're coming from the North, has several toll booths, its the safest road. There's also a road through the mountains from Durango state (East)  to Mazatlan.
 

Ferry.  The "Ferry" travels from La Paz (Baja) to Mazatlan and vice-versa.  The time of crossing is normally 18 hours, departs from La Paz to Mazatlan daily at 3:00pm arrives at Mazatlan at 9:00am

Boat or Yatch. Mazatlan's Marina is located in a really convenient place.
 

           Beam me up Scotty!