Magdalena Bay system itself is as large as San Francisco Bay and mostly undeveloped. Mile after mile of mangrove lined shore, and unique to the area is the Whale Watching Season. Isla Santa Margarita and Isla Magdalena protect Mag Bay from harsher Pacific winds, giving it a calm environment that encourages such rich marine life. For gray whales, which can grow to 35 tons and over 50 feet long, it’s a perfect playground. They travel south from Alaska in the fall, arriving in Mexico to spend the winter, give birth, and mate. About a year later they return to do it again.