The world is largely made up of water and once long before the steam age and later the invention of the airplane the easiest and most practical that a man in those circumstances could make is a raft with a sail made of wood for the crossing of rivers and seas. At the very beginning they used to trade and for the wars, but with great human discoveries from a simple raft, man created large megayachts that are distinguished with the most luxurious content. The aim of this paper is to describe the historical development of yachts, analyze their parts of that dimension, mainsail and its essential characteristics needed for navigation. In addition to sailboats, motor yachts are described, which are the most modern and luxurious yachts in the world. It was also necessary to emphasise the importance of technical controls, namely to ensure the safety of the ship for navigation must satisfy the technical requirements adopted and prescribed by the classification societies in accordance with the Conventions and national Regulations. With a view of the past and human achievements, we can conclude that we are not even aware of the human abilities and how much the naval technology of yachts will thrive.