Between Oho Sima and Simoda no dangers are known to exist; but the northeasterly current must be borne constantly in mind—particularly at night and in thick weather. Its general strength is from two to three miles per hour; but as this, as well as its direction, is much influenced by the local wind, headlands, islands, &c., neither can be relied upon.
Should Oho Sima be obscured by thick weather, before reaching Cape Diamond, endeavor to sight Rock island, for there are no very conspicuous objects on the main land, by which a stranger can recognise the harbor at a distance, and the shore appears as one unbroken line.
To the westward of the harbor there are several sand beaches, and three or four sand banks, These can be plainly discerned when within six or eight miles, and are good landmarks.
A vessel from the southward and eastward should pass to the westward of the island of Kozu Sima,[4] which may be known by a remarkable snow-white cliff on its western side. There is also a white patch on its summit, to the northward of the cliff. From this island the harbor bears N. by W. ½ W., distant about twenty-eight miles.
There are but two hidden dangers in the harbor; the first is the Southampton rock, which lies in mid-channel, bearing N. ½ W. from Vandalia bluff, about three fourths of the way between it and Centre island. This rock is about twenty-five feet in diameter, and has two fathoms water upon it. It is marked by a white spar-buoy.
The second is the Supply rock. Bearing S. by W., a short distance from Buisako islet, and is a sharp rock, with eleven feet water upon it. Its position is designated by a red spar-buoy.
Both of these buoys are securely moored, and the authorities of Simoda have promised to replace them, should they by any cause be removed.
Centre island, which receives its name from being the point from which the treaty limits are measured, is high, conical, and covered with trees. A cave passes entirely through it.
In the outer roads, or mouth of the harbor, a disagreeable swell is sometimes experienced; but inside of the Southampton rock and Centre island, vessels are well sheltered, and the water comparatively smooth. Moor with an open hawse to the southward and westward.
There are good landings for boats in Simoda creek, and at the village of Kakizaki.