Vessels connect La Paz, in Baja Sur, and Mazatlán every day except Saturday; it's an 18-hour trip. Ferries also head from La Paz to Topolobampo, the port at Los Mochis. Reserve a few weeks in advance. The ferries carry passengers with and without vehicles. If you're taking a car to the mainland, you must obtain a vehicle permit before boarding and must have Mexican auto-insurance papers and a tourist card. Tourism officials in La Paz strongly suggest that you obtain the permit and card when crossing the U.S. border into Baja, where offices are better equipped to handle the paperwork than those in La Paz.
Baja Ferries connects La Paz with Topolobampo, the port at Los Mochis, on the mainland, with daily high-speed ferries. The trip takes five hours and costs about $65 per person. Baja Ferries also connects La Paz and Mazatlán; it's an 18-hour trip and costs about $75 per person. You can buy tickets for ferries at the La Paz Pichilingue terminal.
Baja Ferries (La Paz Pichilingue Terminal, La Paz. 612/123-0208. www.bajaferries.com).