A ship bound in, would do well to place a boat on the shoal, that makes off south from the eastern point of Square Rock, as it is called on Beechy’s harbor chart. This shoal can be easily seen from aloft, however, even when there is no swell on. It extends full two cables length from Square Rock to the southward, and is steep. The centre of the shoal is awash with a smooth sea. The tide rises about three feet, and there is a coral rock about one cable’s length north from the northern point of Southern Head, on which I found _eight feet water_. But a ship entering the harbor would not be likely to approach Southern Head so near as to be upon it. This island, as well as those surrounding it, is chiefly visited by whale-ships, and its products, therefore, are such as to suit their wants. Potatoes, yams, and other vegetables, fruits of various kinds, together with wild hogs and goats can be procured from the few whites and Sandwich-islanders—thirty five in all—settled there. Wood is good and plentiful, and water can be had, though in limited quantities, and slightly tainted by the coral rocks from which it springs. The anchorage is fair, though open to the south and west. The reconnoissance made by order of the commander-in-chief, proved the accuracy of Captain Beechy’s chart. Mr. Bennet, acting master of the Susquehanna, says in his report: “Assuming the position of Napa in Great Loo-Choo island, as established by Beechy, to be correct, I find by the mean of my chronometers, that he has placed Ten-Fathom Hole, in Port Lloyd, five miles too far to the westward, and consequently the whole group is placed that much to the westward of its true position.” SAILING DIRECTIONS FOR THE HARBOR OF SIMODA. BY LIEUTENANT WM. L. MAURY, U. S. NAVY. U. S. STEAM-FRIGATE MISSISSIPPI, _Honolulu_, October 26, 1854. Vessels bound to the harbor of Simoda, to the southward and westward, should make Cape Idzu, from which Rock island bears E. S. E. ¼  E., distant about five miles; and if the weather is at all clear, the chain of islands at the entrance of the gulf of Yedo will at the same time be plainly visible. Between Rock island and the main land, there are a number of rocks awash and above water, among which the Japanese junks freely pass, but a ship should not attempt a passage inside of Rock island, unless in case of urgent necessity, particularly as the northeasterly current, which sweeps along this coast, seems to be, at this point, capricious, both in direction and velocity. Giving Rock island a berth of a mile, the harbor of Simoda will be in full view, bearing N. ¼  W., distant five miles. Vandalia Bluff, on the east side of the entrance, may be recognised by a grove of pine-trees on the summit of the bluff, and the village of Susaki, which lies about one third of the way between it and Cape Diamond. Cape Diamond is a sharp point making out to the eastward of the entrance of the harbor.