Application for studying night lights and daytime figures of vessels in accordance with the requirements of the COLREGs-72. The application allows you to observe the night lights of different types of vessels from different angles. Understanding of COLREG navigation lights allows you to correctly estimate vessel position, its maneuvering capabilities and to determine the nature of its work at night time and in poor visibility conditions. The application will be useful to navigators and those who prepare to become one. The app supports dark mode. We welcome comments and suggestions to our e-mail: [email protected]