Which when they had taken up, they used helps, undergirding the ship; and, fearing lest they should fall into the quicksands, strake sail, and so were driven. Undergirding the ship - This method has been used even in modern times. It is called frapping the ship. A stout cable is slipped under the vessel at the prow, which they can conduct to any part of the ship's keel; and then fasten the two ends on the deck, to keep the planks from starting: as many rounds as they please may be thus taken about the vessel. An instance of this kind is mentioned in Lord Anson's Voyage round the World. Speaking of a Spanish man-of-war in a storm: "They were obliged to throw overboard all their upper-deck guns, and take six turns of the cable round the ship, to prevent her opening." P. 24, 4to. edit. The same was done by a British line-of-battle ship in 1763, on her passage from India to the Cape of Good Hope.
The quicksands - Εις την συρτιν, Into the syrt. There were two famous syrts, or quicksands, on the African coast; one called the syrtis major, lying near the coast of Cyrene; and the other, the syrtis minor, not far from Tripoli. Both these, like our Goodwin Sands, were proverbial for their multitude of ship-wrecks. From the direction in which this vessel was driven, it is not at all likely that they were in danger of drifting on any of these syrts, as the vessel does not appear to have been driven near the African coast through the whole of her voyage. And as to what is said, Acts 27:27, of their being driven up and down in Adria, διαφερομενων εν τῳ Αδριᾳ, it must mean their being tossed about near to Sicily, the sea of which is called Adria, according to the old Scholiast upon Dionysius's Periegesis, ver. 85: το Σικελικον τουτο το πελαγος Αδριαν καλουσι· they call this Sicilian sea, Adria. We are therefore to consider that the apprehension, expressed in Acts 27:17, is to be taken generally: they were afraid of falling into some shoals, not knowing in what part of the sea they then were; for they had seen neither sun nor stars for many days; and they had no compass, and consequently could not tell in what direction they were now driving. It is wrong therefore to mark the course of this voyage, as if the vessel had been driven across the whole of the Mediterranean, down to the African coast, and near to the syrts, or shoal banks; to which there is scarcely any reason to believe she had once approximated during the whole of this dangerous voyage.
Strake sail - Χαλασαντες το σκευος. What this means is difficult to say. As to striking or slackening sail, that is entirely out of the question, in such circumstances as they were; when it is evident they could carry no sail at all, and must have gone under bare poles. Some think that lowering the yards, and taking down the top-mast, is what is intended; but in such a perilous situation this would have been of little service. Others think, letting go their main or sheet anchor, is what is meant; but this seems without foundation, as it would have been foolishness in the extreme to have hoped to ride out the storm in such a sea. Passing by a variety of meanings, I suppose cutting away, or by some means letting down the mast, is the action intended to be expressed here; and this would be the most likely means of saving the vessel from foundering.