XVI century vessels take their bows on the high seas.

• Author: Muilenburg, Peter
• Position: 16th century expedition ships

EVERY MIGRANT to the new world in the 16th century had to undergo trial by ordeal. Conquistador, friar, settler, slave . . . all had to cross the formidable North Atlantic in conditions only the desperate would endure today. Survival of the order did not establish innocence--many crimes law waiting to be committed in the Indies--but it did provide justification for intense drives towards wealth, martyrdom, and freedom.

As remarkable as the people were their wooden ships--distinctive craft that shaped history and entered into the collective imagination of succeeding generations as symbols of an unforgettable era. Everyone has heard of Columbus and his caravels, of galleons loaded with treasure, and the swift ships of the corsairs. Yet, when asked to differentiate a caravel from a nao, a galleon from a bergantin, or even a shallop from a trollop, all but experts are lost at sea. With the impending 500th anniversary of the 1492 discoveries bringing a deluge of references to ships, voyages and sailors, now is a good time to get a grip on a watery subject.

SIZING UP THE SHIPS

The caravel and the nao were the workhorses, the galleon, the warhorse of the exploration and exploitation of the Indies. They evolved out of prior experiences in two quite contrasting bodies of water. The Mediterranean Sea was characterized by prolonged calms which left sailing ships at a dead loss. When there was a wind it was flukey, and generally on the nose--that is, directly against whatever direction a boat was heading. The North Atlantic, on the other hand, generated lots of wind and big seas, and if a sailing ship didn't like the wind direction it had only to sit tight in port and await a favourable breeze.

Needless to say, the two areas fostered different types of vessels. The Mediterranean gave rise to the oared galley--easily propelled in the calms with its light, narrow hull of shallow draft and fine ends--and to the lateen rig whose triangular sails could tack against the wind with some efficiency. By contrast, the typical North Atlantic vessel up to medieval times was the cog, a stoutly built, high-sided, bluff-bowed barrel of a boat. It carried one large square sail and rode downwind to its destination.

The caravel was developed from both of these traditions in response to an acute need for a more versatile vessel. When the Portuguese began their explorations down the coast of West Africa in the 15th century, they first sent out an undecked fishing boat with a square sail and a few oars. It ran down the coast of present-day Morocco quickly enough before the prevailing northerly winds and currents, but the return trip took months to complete. Its square sail was hopeless against the wind, and rowing back against a steady current resembled rolling a boulder up a mountain. Something better was called for.

In Portugal, Prince Henry the Navigator had assembled cartographers, astronomers, shipwrights and master mariners to facilitate the African venture. They took the fishing boat and Mediterraneanized it--making it more easily driven, like a galley, by streamlining its hull with narrower lines and a sharper bow. They gave it a trim, capable lateen rig with a big sail forward and a smaller one aft to get the boat back upwind on the home voyage. In place of northern-style lapstrake planking they opted for smooth, edge-to-edge planking for a hull with less drag (to this day such planking is known as caravel). Finally, a full length deck, and a shorter half deck over the stern, made it seaworthy and provided more shelter for the crew.

The caravel, for such it was, resembled a 19th century double-ended ketch, and in performance it was the sweetest sailing vessel of its time. In it Prince Henry had what he wanted--a boat to push ever farther down the African coast, to tack into tight bays, ghost along in light airs, weather heavy seas, and get back home before the crew died. The design proved successful; larger caravels were built, with more masts and decks, and the design spread rapidly throughout Spain and beyond.

When Columbus set out for the Indies, two of his three ships were caravels. Most of the other early explorers favored them as well. Small caravels prosecuted the early Caribbean trade in pearls and Indian slaves, being adept at navigating the intricate channels between reefs and shoals in the Bahamas and through coastal islands in Venezuela.

By this time the caravels sailed under a variety of rigs, depending on how they were used. Lateen (triangular shaped) rigs predominated in coastal waters, but vessels making long offshore passages used the square rig to take better advantage of the following breeze. The Portuguese caravela redonda carried square rig on its foremast and lateen on the others for trips around Africa to India. Columbus changed the rig of the Nina from lateen to square in the Canary Islands just before setting out across the Atlantic. The Nina's new rig was borrowed from the standard North Atlantic cog developed by the Basques and their neighbors in the vigorous pursuit of commerce and piracy. This ship had evolved into the nao (contraction of navio the Spanish word for ship) and now carried more masts with both square and lateen sails.

With slight variations to suit local conditions, the nao was known as a fluyt in Holland, a hulk in Germany, and a carrack in the Mediterranean. In all cases the hull owed its lineage to the cog. Fat and deep, round at bow and stern, the nao was an unabashed, capacious tub--the quintessential merchantman. Topheavy superstructures high above its bow and stern exascerbated its ungainly appearance. These seem so disproportioned to a modern eye that one questions whether artistic depictions were accurate, but they made perfect sense at the time. As trade was expanding, more space for passengers was needed, and as ships took a greater role in warfare the soldiers on board needed shelter. Since sea battles were still being fought with land tactics, forecastles and sterncastles fulfilled the requirements of soldiers and passengers. That these high structures increased windage and made the ships cranky performers mattered little, since they weren't expected to do well to windward.

Then came the introduction of cannon to marine warfare, rendering the idea of wooden castles worse than...