My acquaintance with Captain Booden was at that time somewhat limited, and if possible I knew less of the difficult and narrow exit from Bolinas Bay than I did of Captain Booden. So with great trepidation I jammed the helm hard down, and the obedient little Lively Polly fell off easily, and we were over the bar and gliding gently along under the steep bluff of the Mesa, whose rocky edge, rising sheer from the beach and crowned with dry grass, rose far above the pennon of the little schooner. I did not intend to deceive Captain Booden, but being anxious to work my way down to San Francisco, I had shipped as "able seaman" on the Lively Polly, though it was a long day since I had handled a foresheet or anything bigger than the little plungers which hover about Bolinas Bay, and latterly I had been ranching it at Point Reyes, so what could I know about the bar and the shoals of the harbor, I would like to know? We had glided out of the narrow channel which is skirted on one side by a long sandspit that curves around and makes the southern and western shelter of the bay, and on the other side by a huge elevated tongue of table-land, called by the inhabitants thereabouts the Mesa. High, precipitous, perpendicular, level, and dotted with farm-houses, this singular bit of land stretches several miles out southward to sea, bordered with a rocky beach, and tapered off into the wide ocean with Duxbury Reef--a dangerous rocky reef, curving down to the southward and almost always white with foam, save when the sea is calm, and then the great lazy green waves eddy noiselessly over the half-hidden rocks, or slip like oil over the dreadful dangers which they hide.