34 6 



HYDROGRAPHY. 



which broke over the ship, as high as the foretop, and swept the deck 

 fore and aft. Our situation for several hours was very dangerous ; 

 there was no wind, and it was impossible to change our anchorage. 

 When the signal was made to anchor, part of the squadron got be- 

 yond the bar, in 12 fathoms water, and only experienced a heavy 

 swell. It is better, therefore, for a vessel when off this port to drop 

 anchor in a depth of water above 10 fathoms, either within or outside 

 the bar, particularly at the full and change ; at these periods of the 

 moon, there is always a heavy surf on the coast. It is safer to 

 approach the entrance on the southern side, as the soundings are 

 deeper, and what dangers exist are above water. In steering for the 

 entrance, keep the opening to bear to the northward of northeast-by- 

 east. On that bearing, you will pass the bar in 6 fathoms water, and 

 if towards the south of that bearing, there will be 7 to 9 fathoms, 

 with irregular bottom. 



The entrance to the bay is very striking; on each side bold and 

 rocky cliffs. It is 1 mile wide and 3 miles in length, with deep water 

 and no obstructions. The bay expands and extends north and south 

 beyond the visible horizon. Its length is 36 miles, by an average 

 width of 6 miles ; a large part of its southern, eastern, and northern 

 shores are bordered by wide mud-flats, preventing the landing at low 

 water of even a boat, for nearly the whole distance. The eastern 

 shore may be said to be inaccessible for a distance of 30 miles. In 

 this extensive bay lie several islands ; that of San Angelo is the 

 highest and largest, covered with vegetation to its top. The next in 

 size is Yerba Buena and Alcantras, besides several rocky islets covered 

 with guano, which makes them conspicuous : they usually have im- 

 mense numbers of sea-fowl hovering over them. To the east is the 

 Coast Range, and beyond rise the lofty Californian Mountains, capped 

 with snow, brilliant with all the beautiful tints which the atmosphere 

 of this climate gives. The southern extremity of the bay contracts 

 and ends in several creeks, which make up towards the Embarcadero, 

 Santa Clara, and San Juan. On the north, the bay is bounded by 

 the Straits of San Pablo, which divide it from the bay of that name. 



The Bay of San Pablo is nearly circular, 10 miles in diameter. A 

 channel runs on the east side of the bay to the Strait of Karquines, 

 the mouth of the Sacramento River, where there is sufficient depth 

 of water for large vessels. On the west is an extensive mud-flat, with 



