As the day continued calm, Mark was in no hurry, but passed half an hour in sounding the little bay that was formed by the sunken rocks that lay off the eastern, or weather end of the Crater Reef, as, in a spirit of humility, he insisted on calling that which everybody else now calls Mark’s Reef.  Here he not only found abundance of water for all he wanted, but to his surprise he also found a sandy bottom, formed no doubt by the particles washed from the surrounding rocks under the never-ceasing abrasion of the waves.  On the submerged reef there were only a few inches of water, and our mariners saw clearly that it was possible to secure the ship in this basin, in a very effectual manner, could they only have a sufficiency of good weather in which to do it.

After surveying the basin, itself, with sufficient care, Bob pulled the dingui back towards the ship, Mark sounding as they proceeded.  But two difficulties were found between the points that it was so desirable to bring in communication with each other.  One of these difficulties consisted in a passage between two lines of reef, that ran nearly parallel for a quarter of a mile, and which were only half a cable’s-length asunder.  There was abundance of water between these reefs, but the difficulty was in the course, and in the narrowness of the passage.  Mark passed through the latter four several times, sounding it, as it might be, foot by foot, and examining the bottom with the eye; for, in that pellucid water, with the sun near the zenith, it was possible to see two or three fathoms down, and nowhere did he find any other obstacle than this just mentioned.  Nor was any buoy necessary, the water breaking over the southern end of the outer, and over the northern end of the inner ledge, and nowhere else near by, thus distinctly noting the very two points where it would be necessary to alter the course.

The second obstacle was much more serious than that just described.  It was a reef with a good deal of water over most of it; so much, indeed, that the sea did not break unless in heavy gales, but not enough to carry a ship like the Rancocus over, except in one, and that a very contracted pass, of less than a hundred feet in width.  This channel it would be indispensably necessary to buoy, since a variation from the true course of only a few fathoms would infallibly produce the loss of the ship.  All the rest of the distance was easily enough made by a vessel standing down, by simply taking care not to run into visible breakers.

Mark and Bob did not get back to the Rancocus until near three o’clock.  They found everything as they had left it, and the pigs, poultry and goat, glad enough to see them, and beginning to want their victuals and drink.  The two first are to be found on board of every ship, but the last is not quite so usual.  Captain Crutchely had brought one along to supply milk for his tea, a beverage that, oddly enough, stood second only to grog in his favour.  After Bob had attended to the wants of the brute animals, he and Mark, again sat down on the windlass to make another cold repast on broken meat—­as yet, they had not the hearts to cook anything.  As soon as this homely meal was taken Mark placed a couple of buoys in the dingui, with the pig-iron that was necessary to anchor them, and proceeded to the spot on the reef, where it was proposed to place them.