Brave Old Salt by Oliver Optic

Through the deep darkness and the dense fog the boat made its way. There was not an object to be seen, on ship or shore, to guide its course; and in front of Somers there was a patent binnacle, whose lights were reflected on the compass, but did not even soften the gloom without, into which he continued to gaze with the most anxious solicitude. He had carefully estimated the currents the whale-boat would encounter, and calculated the force of the wind, so as to determine her lee-way with the nicest practicable accuracy.

The young commander of the expedition hoped to strike a certain point of the land to the eastward of the fort on Mobile Point, distant five and a half miles from the ship. Half a mile east or west of the desired point might involve him in serious if not fatal difficulties, and everything depended upon the accuracy of his calculations. His early experience as a boatman at Pinchbrook Harbor was of incalculable service to him, since nothing can supply the place of actual observation in the making of such nice estimates as were required for success in the present instance.