The Silva Clinometer is used for checking the heeling angle on sailing boats and for the power-trim check on powerboats. It is also a perfect working instrument for other applications, such as making sure that different vehicles and equipment sits "level" or keep the desired a angle.For angles up to 5deg, read the top precise scale, for angles over 5deg, use the lower scale for readings up to 35deg. FeaturesHeeling angle - displays the heeling angle on sailing boats and the power-trim check on powerboats.Steady mounting - keeps in place, even in rough conditionsEasy to read - safe and swift reading so you can set the right course