But although, to the unsophisticated fishermen of Sagua la Grande, the mysterious warship appeared to be bound north, she was really bound south-east through the Nicholas and Old Bahama channels: and when the yacht had made an offing of some fifteen miles--by which time she was of course out of sight of the fishermen's boats, Milsom ordered the helm to be ported and the engines sent full speed ahead, she having by that time run on to a line which the ex-Navy man had pencilled on his chart as the probable course of the convict steamer; and if that craft had left Havana at the hour arranged, and were steaming at the rate which the harbour-master had anticipated would be her pace, she must now be nearly sixty miles ahead. That was a fairly long lead, certainly; but there is a big difference between a speed of eight knots and that of twenty-four, and Milsom calculated that, if the _Maranon_ were really ahead of them, they ought to overtake her in something like three hours. As a matter of fact, they sighted the craft dead ahead about five bells in the afternoon watch, identified her to their entire satisfaction about half an hour later, and passed her, some sixteen miles to the southward, about one bell in the first "dog." "Now," said Milsom, when he came down from aloft after personally satisfying himself as to the identity of the great, dirty-white, rust- streaked hull crawling along in the northern board, "let me make a little calculation. Our plan is to appear ahead of her, steaming to the northward and westward--to meet her, in fact, instead of overtaking her; and the proper time to do this will be about a quarter of an hour before sunset. I take it that she is steaming at about the pace which my friend the harbour-master allowed her--that is to say, about eight knots. At that rate she will be about eight miles farther to the eastward at a quarter of an hour before sunset. That means that--um-- um--yes, that will be about right. Now, Jack, my hearty, cheer up! for unless something goes very radically wrong with our scheme, our friends ought to be safe and snug aboard this dandy little hooker in a couple of hours' time. Now, it is you, my friend, who are going to play the giddy pirate and wrest our friends, at the sword's point, out of the hands of the oppressor, so cut away down below, my lad, and get into your disguise; and while you are doing that the deck hands can be doing the same, so as to render it impossible for them to be identified at any future time, should they be met in the streets of Havana, or elsewhere, by anybody belonging to the _Maranon_."