My wife hiked through Embarcadero Marina Park South as a part of a longer hike to Chicano Park. You can see the entire log of that hike here - http://hikingtrailhead.com/Logs/ShowLog.aspx?LogID=182072. Embarcadero Marina Park South is a large, beautiful park beautifully situated near the water. You cannot walk directly from the north section of Embarcadero Marina Park to the south section. They are separate "islands", but both are very nice spots.