Battery Menshikov in summer

The battery and the pier are painted with mysterious numbers and circles. For what? They are designed to determine the deviation of the magnetic compasses on the ship. Here exactly is a deviation range. When determining the deviation with a magnetic compass direction finder, they take a bearing to the dome of the Naval Cathedral and get the actual magnetic bearing, and the true bearing is written on the walls, the numbers are degrees, and the circles are half a degree. Knowledgeable people say that this test site is considered the best in the country in terms of accuracy and convenience.