pitched forward, thus lessening the violent turbulence caused by waves. Treasure ships also used floating anchors cast off the sides of the ship in order to increase stability. The stern had two 2.5 m (8 foot) iron anchors weighing over a thousand pounds each, used for mooring offshore. Like many Chinese anchors, these had four flukes set at a sharp angle against the main shaft. Watertight compartments were also used to add strength to the treasure ships. The ships also had a balanced rudder which could be raised and lowered, creating additional stability like an extra keel. The balanced rudder placed as much of the rudder forward of the stern post as behind it, making such large ships easier to steer. Unlike a typical fuchuan warship, the treasure ships had nine staggered masts and twelve square sails, increasing its speed. Treasure ships also had 24 cast-bronze cannons with a maximum range of 240 to 275 m (800–900 feet). However, treasure ships were considered luxury ships rather than warships. As such, they lacked the fuchuan's raised platforms or extended planks used for battle. Non-gunpowder weapons on Zheng He's vessels seems to be bows. For gunpowder weapons, they carried bombards (albeit shorter than Portuguese bombards) and various kind of hand cannons, such as can be found on early 15th century Bakau shipwreck. Comparing with Penglai wrecks, the fleet may have carried cannons with bowl-shaped muzzle (which dates back to late Yuan dynasty), and iron cannons with several rings on their muzzle (in the wrecks they are 76 and 73 cm long, weighing 110 and 74 kg), which according to Tang Zhiba, a typical of early Ming iron cannon. They may also carry incendiary bombs (quicklime bottles). Girolamo Sernigi (1499) gives an account of the armament of what possibly the Chinese vessels: It is now about 80 years since there arrived in this city of Chalicut certain vessels of white Christians, who wore their hair long like Germans, and had no beards except around the mouth, such as are worn at Constantinople by cavaliers and courtiers. They landed, wearing a cuirass, helmet, and visor, and carrying a certain weapon [sword] attached to a spear. Their vessels are armed with bombards, shorter than those in use with us. Once every two years they return with 20 or 25 vessels. They are unable to tell what people they are, nor what merchandise they bring to