1202 AD, Venice: An enormous naval fleet is moored in the Venetian lagoon, awaiting its passengers: a coalition force of European crusaders, about to sail to Egypt to liberate Jerusalem. A trouble-making Welshman, fleeing his unsavory past, finds himself in the clutches of Gregor of Mainz, a soldier determined to take the Welshman on crusade “to cleanse him of his sins.” Against his will, he is berthed on the Venus, the ship designated for the prostitutes and other camp-followers.

Before the fleet sets sail, Gregor and his cousin Otto are guests at the home of a pompous Venetian nobleman, Barzizza. They bring along the Welshman – who narrates the following excerpts – to keep an eye on him.

Barzizza spent much of the meal preaching the dangers and discomforts of sea-travel, of which he had decades of experience. He warned at least seven times to take plenty of laxatives (he recommended pennyroyal, smeared onto the body with oil and vinegar), for constipation was a discomfort nobody could escape from. He offered remedies for seasickness; he told us to avoid local fish, poultry, and soft cheeses, but to trust hard cheeses and heavily spiced sweetmeats; he hoped we had all thought to write out wills before departing, and he could get them notarized for us at a discount in San Marco square; he warned us that once you get salt water on you, you never dry out but remain forever sticky; he advised us to adapt a sailor’s stance, knees bent and legs wide apart; he warned against seasickness and said the best cure for it was to stay above deck and stand in the middle of the ship (where it rocked less), and stare at the horizon; he told us the mariners had a strange lingo of their own that we’d do well to learn if ever we hoped to understand them. He also alerted us to the superstitions of sailors the world over, so that we would do nothing to cause dismay and get us thrown overboard as harbingers of bad luck. We must not step onto the boat with our left foot; nor throw stones overboard; nor look back at the port once setting out on the journey; nor kill any dolphins (whatever those were), albatrosses (ditto), or gulls (gulls I remembered from the Channel crossing); nor cut our hair or nails while at sea; nor utter the word drowned; nor whistle; nor have women or priests on board (although obviously some adjustments would have to be made in that regard); and above all, we must not throw the sailors’ cats overboard, for nothing could be more certain of inciting the displeasure of the gods, cats being the luckiest thing one could have on board (as well as the only way to control the mice and rats). And these injunctions were for us who were merely passengers; for the mariners themselves there was an entire unwritten testament of shalts and shalt-nots, regarding rigging, fixing, mending, charting courses.

Many of the transport vessels had towers built fore and aft on the decks; these would be added to later on, and used to besiege the high harbor walls of infidel cities. In the meantime, the cabins within these “castles” were partitioned off into miniscule closets for the highest ranking pilgrims on board; below decks was divided into several long, cramped dormitories, each of which reeked of vinegar, and each of which housed a dozen knights, their squires, and chests full of their arms and armor; others would travel on the horse transports, watching the mounts; infantry were crammed in even tighter on other vessels. Upon appropriating me, Gregor had bargained at a high price to have a little extra room.

On Gregor’s orders, they took me via gondola to the main island, the buzzing Rialto, and purchased things for me that I protested I would never need: extra clothes, a quilt, a water skin, bedding, charms to ward off seasickness and bad luck. They also purchased a cage of half a dozen hens, grapes, and wild mushrooms (in abundance), and vile-looking dried herbs with poetic names like “Common Fumitory” and “Toadflax” that they explained would make it possible to defecate at sea.

The morning came bright and sunny, with a favorable wind. This relieved the mariners, for we’d already missed the northwesterly melteme wind farther east; they were worried we’d also lose the bora, the wind from the Dolomites that made eastward passage easier this time of year. To a ridiculous amount of fanfare, Enrico Dandolo, the ancient, blind Doge of Venice – who had dramatically taken the cross himself a few weeks earlier, just as I was arriving in Venice – was ferried out to his ship, meandering through the moored fleet so that we all could get a glimpse of him.

Dandolo was formidable, despite his age. He was not large, but he was tough as dried meat, lean and seared by decades of salt water and sun. He was no bureaucratic quill-pusher; he had put in his time traversing the great sea before being elected Doge. And the blindness, mariners whispered reverentially, was relatively recent, an accident in a far-off place called Constantinople; before that, he had put in years as a soldier too. Three decades older than the elegant courtier commanding the army – Boniface of Montferrat – Dandolo looked as if he might have wrestled him to a draw. He wore long, bright robes with swirls on them, and a sash rather than a belt; also, a gold cap almost like a crown. His was the largest galley, with three hundred rowers, the hull painted bright vermilion, the red sails topped with silk decorations. Although the last to be boarded, it would be the first to leave the harbor, the winged lion of St. Mark fluttering from the flags at the top of both masts, trumpets and timbrels playing loudly on the deck.

Once the sails were up, there was a surfeit of coils lying on the deck, which the sailors would soon spend hours laying straight, untwisting, and coiling up again. Cooking fires were stoked; depending on the ship, these were either in the hold or up on the raised deck in the stern (the mariners for some reason called this the poop deck). Wine was splashed liberally across the deck of every ship, a symbolic offering to ancient sea gods – which struck me as, first, a desperate waste of wine and second, a decidedly queer way to begin a Christian pilgrimage. The master of each ship shouted at his crews, and not quite in concert, all burst into a queasy rendition of Veni Creator Spiritus. Ship after ship after ship sailed or rowed out; the sea looked like a bobbing city when all the vessels were out – the rowed galleys, the transports, the horse-transports, some pulling barges and long boats behind. On the fore-deck of every ship was an array of crossbowmen, well-heeled Venetian youths. Fifty of the galleys were Venice’s contribution; each other ship (or collection thereof) carried a noble lord and his followers. Bishop Conrad of Halberstadt was high lord of the Innocent, but the Venus lacked such patronage. Somebody told me the fleet would make a chain three miles long. As we sailed from the lagoon, sails caught the wind and unfurled with a noise so thunderous I was afraid I might go deaf. It was a stupefying sight, all those sails – enough hemp-canvas and silk to drape over all of Venice.

Being out on the open sea was riotously loud in a way I did not remember from my daylong passage to the continent, three years earlier. Every imaginable pitch of creaking surrounded us relentlessly: Sometimes it was timber against timber, or tarred gunk (oakum, to those in the know) shrieking as it was pinched and pierced between the planks of the hull, or line straining within wooden blocks; sails shivered so loudly they seemed to be speaking to the gods, especially when they went briefly slack; the drums that set a tempo for the galley rowers rumbled in everyone’s ears; rigging made all sorts of ghastly noises I’d never’ve guessed simple line could make. Even the birds (for there were always birds, those scavengers) were screechers.

The wind was fresh but cold, and unrelenting, and ripped words out of our mouths. The mariners spoke, but always with few words, as if a phrase contained a paragraph: “This wind,” “Zara,” “Byzantium,” “the other line” – these were treated as engrossing monologues.

The sway of the boat was like nothing I had experienced before, except for that dismal crossing of “the sleeve” – the water ineffectually protecting Britain from the barbarian hoards. Those who compare being shipboard to riding a leisurely cantering horse are sorely wrong; it would have to be a lame horse with legs a dozen yards long each, that never stops for breath and bucks every few moments for good measure. The sensation of what ought to be solid, forever moving under one’s feet – this is not an experience the gods ever intended mortals to endure. For most of the day, the sun was of a staggering strength, its reflection glaring up from below almost as badly as the real thing glared from above. Jamila seemed completely immune to the trauma of it, and spent most of her time below, where the wind and sun did not trouble her, although the heeling of the boat seemed even worse, in the dark and stink.

For the first several hours, almost all of the women above deck were falling over on top of each other on the curved deck, grabbing at whatever they could for balance – heavy coils of line, shrouds, masts, trunks lashed down along the bulwarks – and being ordered by shouting mariners to stay put. I settled down amidships, for Barzizza was right: Things rocked less here. I thought about the war horses in the transports, and wondered how they would manage. Otto had explained they were each supported in a sling, so the worst of the rolling would not lame them . . . still it must be hell for them. Once they let the animals out for grazing, whenever they made land, they’d never get them back into the ships.

The mariners themselves were a wonder to behold. Unlike us landsmen, they related to the ship the way a knight does to his horse, or I to my harp: intuitively, intimately, subtly. All were sunburned, and I could never tell their ages, for there were young men with old faces and old men with bodies limber as any youth. The master of the ship stood on the poop deck and spent the entire day, it seemed, just gazing about us. He had two boys posted to either side. If he felt we were moving too close to another ship (it really was like a city under sail), he’d call out to the boys, who in turn would shout down to the helmsman, who in turn would pull on lines to steer the rudders that stuck out to either side of the ship like oversized oars. Meanwhile the sailors would await instruction, then leap with the uniformity of a school of fish when orders were barked at them. They pulled some halyards together, four or five men on one line, moving like acrobats. It entertained me (for a while) that they would pull on things in one place, and a lateen sail would rise in some other part of the boat, tied to yards that were in turn attached to the towering masts.

We’d be always within sight of land, because the Venetians would need to spend a good part of every third day refilling the galley rowers’ water supply. At such stops, temporary crewmen would be hired, who knew the local hazards. It took time to negotiate with these men. The days were growing shorter, and because of the shoals in the Adriatic, it was not safe to travel but in good daylight. It would be a long trip south.

A few hours into the ordeal, I misjudged a step and nearly fell into the sea; we were going at such a fast clip, I doubt they’d have stopped for me, and suddenly I was acutely aware of my own mortality as something that I needed – even wanted – to avoid.

I learned, this first day, that sailors don’t like having women on their boats, because of some fear involving mermaids. (This makes no sense to me: If the danger of a mermaid is that she’ll lure a man into the water, why not keep pretty women around to entice you to remain on board? I tried this argument with many of the sailors but they maintained their fear, almost as if they were proud of it.) The most superstitious of the sailors had refused to crew the whore-boats, and so the mariners on the Venus were of two types: the ones who were not at all superstitious; and the ones who had decided they could get over their fears if a high enough price was paid, in either flesh or money. The former group quickly saw the benefit of pretending to belong to the latter group. The whores – who were the savviest unit in the army – had anticipated all of this, and planned accordingly. Ours was possibly the most convivial vessel on the whole of the Adriatic.

Excerpted and adapted from Crossed: A Novel of the Fourth Crusade (William Morrow, February 2008) by Nicole Galland. The Vineyard Haven writer, who grew up in West Tisbury, is also the author of The Fool’s Tale and Revenge of the Rose.