When Morgan received the news that San Lorenzo had been stormed, he began to send aboard the meat, maize, and cassava he had collected in Santa Katalina. He had already blown the Spanish forts to pieces, with the one exception of the fort of St Teresa. He now took all the captured Spanish guns, and flung them into the sea, where they lie still, among the scarlet coral sprays. The Spanish town was then burnt, and the Spanish prisoners placed aboard the ships. It was Morgan's intention to return to the island after sacking Panama, and to leave there a strong garrison to hold it in the interests of the buccaneers. When he had made these preparations he weighed his anchors, and sailed for the Chagres River under the English colours.
Eight days later they came sailing slowly up towards the river's mouth. Their joy was so great "when they saw the English colours upon the castle, that they minded not their way into the river," being gathered at the rum cask instead of at the lead, and calling healths instead of soundings. As a consequence, four ships of the fleet, including the admiral's flagship, ran foul of the ledge of rocks at the river's entry. Several men were drowned, but the goods and ships' stores were saved, though with some difficulty. As they got out warps to bring the ships off, the north wind freshened. In shallow water, such as that, a sea rises very quickly. In a few hours a regular "norther" had set in, and the ships beat to pieces on the ledge before the end of the day.
As Morgan came ashore at the port, the guns were fired in salute, and the pirates lined the quay and the castle walls to give him a triumphant welcome. He examined the castle, questioned the lieutenants, and at once took steps to repair the damage done by the fire. The thirty survivors of the garrison and all the prisoners from Santa Katalina, were set to work to drive in new palisadoes in the place of those burnt in the attack. The huts were rethatched and the whole place reordered. There were some Spanish ships in the port whose crews had been pressed into the Spanish garrison at the time of the storm. They were comparatively small, of the kind known as chatas, or chatten, a sort of coast boat of slight draught, used for river work and for the conveyance of goods from the Chagres to the cities on the Main. They had iron and brass guns aboard them, which were hoisted out, and mounted in the fort. Captain Morgan then picked a garrison of 500 buccaneers to hold the fort, under a buccaneer named Norman. He placed 150 more in the ships in the anchorage, and embarked the remainder in flat-bottomed boats for the voyage up the Chagres.
It was the dry season, so that the river, at times so turbulent, was dwindled to a tenth of its volume. In order that the hard work of hauling boats over shallows might not be made still harder, Morgan gave orders that the men should take but scanty stock of provisions. A few maize cobs and a strip or two of charqui was all the travelling store in the scrips his pilgrims carried. They hoped that they would find fresh food in the Spanish strongholds, or ambuscades, which guarded the passage over the isthmus.
The company set sail from San Lorenzo on the morning of the 12th (one says the 18th) of January 1671. They numbered in all 1200 men, packed into thirty-two canoas and the five chatas they had taken in the port. His guides went on ahead in one of the chatas, with her guns aboard her and the matches lit, and one Robert Delander, a buccaneer captain, in command. The first day's sailing against a gentle current was pleasant enough. In spite of the heat and the overcrowding of the boats, they made six leagues between dawn and sunset, and anchored at a place called De los Bracos. Here a number of the pirates went ashore to sleep "and stretch their limbs, they being almost crippled with lying too much crowded in the boats." They also foraged up and down for food in the plantations; but the Spaniards had fled with all their stores. It was the first day of the journey over the isthmus, yet many of the men had already come to an end of their provisions. "The greatest part of them" ate nothing all day, nor enjoyed "any other refreshment" than a pipe of tobacco. The next day, "very early in the morning," before the sun rose, they shoved off from the mooring-place. They rowed all day, suffering much from the mosquitoes, but made little progress. The river was fallen very low, so that they were rowing or poling over a series of pools joined by shallow rapids. To each side of them were stretches of black, alluvial mud, already springing green with shrubs and water-plants. Every now and then, as they rowed on, on the dim, sluggish, silent, steaming river, they butted a sleeping alligator as he sunned in the shallows, or were stopped by a fallen tree, brought by the summer floods and left to rot there. At twilight, when the crying of the birds became more intense and the monkeys gathered to their screaming in the treetops, the boats drew up to the bank at a planter's station, or wayside shrine, known as Cruz de Juan Gallego. Here they went ashore to sleep, still gnawed with famine, and faint with the hard day's rowing. The guides told Henry Morgan that after another two leagues they might leave the boats, and push through the woods on foot.
Early the next morning the admiral decided to leave the boats, for with his men so faint from hunger he thought it dangerous to tax them with a labour so severe as rowing. He left 160 men to protect the fleet, giving them the strictest orders to remain aboard. "No man," he commanded, "upon any pretext whatsoever, should dare to leave the boats and go ashore." The woods there were so dark and thick that a Spanish garrison might have lain within 100 yards of the fleet, and cut off any stragglers who landed. Having given his orders, he chose out a gang of macheteros, or men carrying the sharp sword-like machetes, to march ahead of the main body, to cut a trackway in the pulpy green stuff. They then set forward through the forest, over their ankles in swampy mud, up to their knees sometimes in rotting leaves, clambering over giant tree trunks, wading through stagnant brooks, staggering and slipping and swearing, faint with famine; a very desperate gang of cut-throats. As they marched, the things called garapatadas, or wood-ticks, of which some six sorts flourish there, dropped down upon them in scores, to add their burning bites to the venom of the mosquitoes. In a moist atmosphere of at least 90°, with heavy arms to carry, that march must have been terrible. Even the buccaneers, men hardened to the climate, could not endure it: they straggled back to the boats, and re-embarked.
With a great deal of trouble the pirates dragged the boats "to a place farther up the river, called Cedro Bueno," where they halted for the stragglers, who drifted in during the evening. Here they went ashore to a wretched bivouac, to lie about the camp fires, with their belts drawn tight, chewing grass or aromatic leaves to allay their hunger. After Cedro Bueno the river narrowed, so that there was rather more water to float the canoas. The land, too, was less densely wooded, and easier for the men to march upon. On the fourth day "the greatest part of the Pirates marched by land, being led by one of the guides." Another guide led the rest of them in the canoas; two boats going ahead of the main fleet, one on each side of the river, to discover "the ambuscades of the Spaniards." The Spaniards had lined the river-banks at intervals with Indian spies, who were so "very dexterous" that they brought intelligence of the coming of the pirates "six hours at least before they came to any place." About noon on this day, as the boats neared Torna Cavallos, one of the guides cried out that he saw an ambuscade. "His voice caused infinite joy to all the Pirates," who made sure that the fastness would be well provisioned, and that at last they might "afford something to the ferment of their stomachs, which now was grown so sharp that it did gnaw their very bowels." The place was carried with a rush; but the redoubt was empty. The Spaniards had all fled away some hours before, when their spies had come in from down the river. There had been 500 Spaniards there standing to arms behind the barricade of tree trunks. They had marched away with all their gear, save only a few leather bags, "all empty," and a few crusts and bread crumbs "upon the ground where they had eaten." There were a few shelter huts, thatched with palm leaves, within the barricade. These the pirates tore to pieces in the fury of their disappointment. They fell upon the leather bags like hungry dogs quarrelling for a bone. They fought and wrangled for the scraps of leather, and ate them greedily, "with frequent gulps of water." Had they taken any Spaniards there "they would certainly in that occasion [or want] have roasted or boiled" them "to satisfy their famine."
Somewhat relieved by the scraps of leather, they marched on along the river-bank to "another post called Torna Munni." Here they found a second wall of tree trunks, loopholed for musketry, "but as barren and desert as the former." They sought about in the woods for fruits or roots, but could find nothing—"the Spaniards having been so provident as not to leave behind them anywhere the least crumb of sustenance." There was nothing for them but "those pieces of leather, so hard and dry," a few of which had been saved "for supper" by the more provident. He who had a little scrap of hide, would slice it into strips, "and beat it between two stones, and rub it, often dipping it in the water of the river, to render it by these means supple and tender." Lastly, the hair was scraped off, and the piece "roasted or broiled" at the camp fire upon a spit of lance wood. "And being thus cooked they cut it into small morsels, and eat it," chewing each bit for several minutes as though loth to lose it, and helping it down "with frequent gulps of water." There was plenty of fish in the Chagres, but perhaps they had no lines. It seems strange, however, that they made no attempt to kill some of the myriads of birds and monkeys in the trees, or the edible snakes which swarm in the grass, or, as a last resource, the alligators in the river.