Starting in December 2013, the 64-passenger Safari Voyager takes over the Safari Endeavour's Sea of Cortés routes, cruising year-round. Seven-night round-trip itineraries from San José del Cabo include "Baja's Whale Bounty" and "Cousteau's Aquarium of the World." The seven-night round-trip cruise out of Guaymas, mainland Mexico, focuses on the "Marine Miracles of Baja California." The 14-night one-way cruise between Guaymas and San José del Cabo explores the "Essential Islands of Baja California North and South."

There are three cruise styles. Ships in the "Wilderness" category focus on active adventure. "Safari"-designated ships offer soft adventure with a touch of luxury. The "Heritage" designation offers living history aboard ship and portside.

Cabins are priced per person, double occupancy, starting at $2,995 in low season. Rates include port fees and taxes, airport transfers, park entrance fees, sports equipment, guided hikes, yoga classes, a wellness program and all onboard guide services. More info: 1-888-862-8881; www.un-cruise.com.