The nef in its later manifestations became a much more seaworthy vessel than this, with four masts, the two foremost ones square-rigged and carrying courses and topsails, the two after ones carrying lateen sails; the latter from their small size and their proximity to one another could not have had much effect on the sailing qualities of the ship.  The nefs in the fleet of Don John of Austria in 1571 were rigged in this fashion and comprised vessels of eight hundred, nine hundred, and even one thousand tons, while a contemporary English vessel, the Great Harry or Henri Grace a Dieu, was as much as fifteen hundred tons, and carried no less than one hundred and eighty-four pieces of ordnance.  It was from the nef and the galeasse that the sailing man-of-war arrived by the process of evolution.  The galley in the first instance was the vessel of men who fought hand to hand, the men in whom personal strength and desperate valour were blended, who desired nothing so much as to come to close grips with their enemy.  Such rude engines of war as the pierriers, or short cannons which discharged some forty or fifty pounds of broken stone upon the enemy, were first mounted in the galley; these were followed by improved artillery as time went on.  But although the galleys eventually carried quite big guns, as instanced by the forty-eight pounder in the galleys of the Knights of St. John, still it soon became apparent that the limit was reached by guns of this weight; the galley was essentially a light vessel and was not built to withstand those rude shocks caused by firing heavy charges of powder.

The galeasse was the connecting link between the navy of oars and the navy of sails.  The navy of oars was in its generation apt for warlike purposes; but it was in its essence a force analogous to the light cavalry of the land; useful for a raid, a sudden dash, but without that great strength and solidity which came in later years to the building of the sailing line of battleship.

The galeasse was really a magnified galley, one which used both sails and oars, on board of which the rowers were under cover; she was built with a forecastle and a sterncastle which were elevated some six feet above the benches of the rowers, and her very long and immensely heavy oars were of course proportionate to the size of the vessel.  The description of a galeasse of nearly one thousand tons burden is set forth as follows by Jurien de la Graviere: 

“Her draught of water was about 18 feet 6 inches, she was propelled by 52 oars, 48 feet in length, each oar being worked by 9 men.  Her crew consisted of 452 rowers, 350 soldiers, 60 marines, 12 steersmen, 40 ordinary seamen, 86 cannoneers, 12 petty officers, 4 boatswains’ mates, 3 pilots, 2 sub-pilots, 4 counsellors, 2 surgeons, 4 writers, 2 sergeants, 2 carpenters, 2 caulkers, 2 coopers, 2 bakers, 10 servants, a captain, a lieutenant, a purser.  In all some thousand men, or about the same number as the crew of a three-decker of a later date.”

The fleet of the “Holy League” at the battle of Lepanto had in it six galeasses from the arsenal of Venice; and whereas an average galley carried 110 soldiers and 222 galley slaves, the crews of these galeasses comprised 270 soldiers, 130 sailors, and 300 galley slaves.