Junk (ship) Junk (ship) Junk is a type of ancient Chinese sailing ship that is still in use today. Junks were used as seagoing vessels as early as the 2nd century AD and developed rapidly during the Song dynasty (960–1279). They evolved in the later dynasties, and were used throughout Asia for extensive ocean voyages. They were found, and in lesser numbers are still found, throughout South-East Asia and India, but primarily in China. Found more broadly today is a growing number of modern recreational junk-rigged sailboats. The term "junk" may be used to cover many kinds of boat—ocean-going, cargo-carrying, pleasure boats,
Pontoon effect side than the center of buoyancy can go. At this point, the righting force will disappear, replaced by a turning moment in the opposite direction. This can capsize the vessel at the point at which one pontoon is completely submerged. When using twin lateral pontoons, each pontoon should have enough buoyancy to bear the load of the entire vessel on its own. If the vessel is so heavy that either pontoon is mostly submerged when no lateral force is applied, it will be vulnerable to the pontoon effect. If sufficient lateral force arises (such as wind or shifting load), the