The "Mary Rose" represented a transitional ship design in naval warfare. Since ancient times, war at sea had been fought much like that on land: with melee weapons and bows and arrows, but on floating wooden platforms rather than battlefields. Though the introduction of guns was a significant change, it only slowly changed the dynamics of ship-to-ship combat. As guns became heavier and able to take more powerful gunpowder charges, they needed to be placed lower in the ship, closer to the water line. Gunports cut in the hull of ships had been introduced as early as 1501, only about a decade before the "Mary Rose" was built. This made broadsides, coordinated volleys from all the guns on one side of a ship, possible for the first time in history, at least in theory. Naval tactics throughout the 16th century and well into the 17th century focused on countering the oar-powered galleys that were armed with heavy guns in the bow, facing forwards, which were aimed by turning the entire ship against its target. Combined with inefficient gunpowder and the difficulties inherent in firing accurately from moving platforms, this meant that boarding remained the primary tactic for decisive victory throughout the 16th century.