They are only about sixty feet or so in height clear above the level of the sea; and, consequently, being only visible at a comparatively short distance off--not more than a couple of leagues at the outside, even in broad daylight--and situated as the shoal is in the direct track of the trade wind, the rocks form a source of great peril to mariners traversing their bearings, especially at night time, nothing existing to give warning of their proximity until a vessel may be right on to them, as it were.
Thinking of all this, which I had read in the "Sailing Directions for the North Atlantic," a book which the skipper had lent me to study, in order to perfect me in navigation, I felt a sudden fear lest the ship should be wrecked on the reef, making up my mind to tell Jorrocks about the error I had discovered in our position on the chart, which I determined to ask him to fetch for me, so as to show it to Captain Billings.
Jorrocks, however, was a long time coming forwards after being relieved from charge of the deck by Mr Macdougall, remaining some little time talking to him on the poop; so that it was nearly two bells, and quite dusky, when he made his way to where I was standing looking out for him, I having asked one of the hands to say that I wanted to speak with him.
"Well, Mister Leigh," he said, on making his appearance, "here I am at last; better late nor never, as the old folks say! But that blessed Scotchman would have a long yarn with me, about goodness knows what!" "I'm glad you've come," I replied; and then I went on to tell him about my fears of peril to the ship from our vicinity to the Rocks of Saint Paul, which I was certain we were approaching every mile we ran further west.
But the boatswain was almost as incredulous of our being near the shoal as the first mate had been in the afternoon.
"Bless you, Mister Leigh, we're miles to windward of that place," said he with a laugh.

"But it's allers the way with your young navigators as is full chock up to the bung with book larnin' and hasn't had no real 'sperience o' the sea yet! They allers fancy all sorts o' dangers that your old seamen who've been a v'yage or two never thinks o' reckonin' on!" However, the good-natured fellow, seeing how earnest I was in the matter, promised to take the chart to the skipper, who was lying down in his cabin again, feeling far from well of late, as, indeed, his looks lately showed--and we were all afraid he had caught the same sort of low fever like Mr Ohlsen, the second mate.
"An; I'll tell him as mildly as I can, Mister Leigh, of this here mare's nest as you've found out, so as not to make him angry with you again." "Thank you, Jorrocks," I replied heartily; but, just at that moment, hearing the whales making a noise quite close to the ship's side as I thought--although I could not see them within the limited circle of dusky light to which the surrounding gloom narrowed my vision, I said, "What a row those whales are making, are they not?
They're quite near, and yet, although it's not dark enough yet to hide them from our gaze, there's not a trace of one in sight!" Jorrocks cocked his head on one side and listened; but in an instant there was a striking alteration in the quizzical look with which he had at first regarded me, under the evident idea that I had discovered another "mare's nest." "By Jingo, Mister Leigh, you're right after all!" he exclaimed, his face turning pale as if with sudden fright.
"What, do you think we're running on the rocks I spoke about ?" I asked, anxiously.
"Aye, not a doubt of it," he answered, in the same quick way, bending his head again to listen over the side.

"Either them identical ones, or else we're on the Rocas off the Brazilian coast." In another moment, however, if in doubt previously, his suspicions were apparently confirmed; for, springing up again, and rushing aft as if he were suddenly possessed, Jorrocks roared out at the pitch of his voice-- the words ringing like a trumpet note through the ship-- "Breakers ahead on the weather bow! Hard up with the helm--hard!".