Strictly speaking, you have two kinds of yachts that you will see leave your ports. The first craft does have an engine but in the interests of sportsmanship and yachting prowess, this vessel, built mainly out of wood, will be crossing the seas using only its huge sails. But the engine is necessary to allow this vessel to leave its busy port. Traffic is heavy at the best of times, so no accidents should be permissible. In any event, such incidents are rare.
All yacht captains have their piloting licenses. The engineers on board are also licensed. Most economically developed cities have strict laws that extend to several hundred nautical miles outside of their ports. And there are global laws of the sea to be observed as well. The second type of yacht is not used for sport. It is most certainly not used for deep sea fishing either, although you will find guests indulging in a bit of legal tuna or marlin fishing for recreational purposes from time to time.
These gigantic, majestic ocean going crafts, comparable to your luxury cruise liners, are best secured through your consummate globally aware yacht dealer or broker. Most busy ports will have a booking or sales office for you to visit, but should you not be able to reach such a salesman at this time, you can contact him via his online yacht registry. For most men and women with nautical aspirations, acquiring such a yacht for keeps can only happen in dreams.
Have you any idea just how much these giants of the ocean cost these days, even if purchased second hand? But never mind that, you can secure charters or rent these boats for short term periods.