An instrument similar to a mariner's compass, but without magnetic needles, and having two sight vanes by which bearings are taken, esp. such as cannot be taken by the compass.
A card marked in degrees and having sightings on it that is used to take bearings relative to the ship, rather than magnetic bearings as taken with a compass.
An instrument used on a vessel in connection with a current line and current pole to obtain the set of the current. In its simplest form, it is a disk about 8 inches in diameter and graduated clockwise for every 5° or 10°. It is mounted rigidly on the vessel, usually with the 0° mark forward and the diameter through this mark parallel with the keel. Bearings are then related to the vessel's compass and converted to true.
a compass card that lists the bearings, or directions, for the ship
a compass-like device that measures the bearing of a landmark in relation to a ship
a navigational instrument resembling a mariner's compass without magnetic needles and having two sight vanes which bearings are taken -- Webster Dictionary
a sighting device attached to a ship's compass
A horizontal protractor with a swiveling gun sight. Used for navigating in coastal waters; bearings could be taken on buoys, lighthouses, or land features. Of course, if fog set in, you could lose your bearings and run aground.
An instrument for sighting relative bearings.
navigational instrument used in taking bearings; consists of two sight vanes mounted on a hoop revolving about a dumb compass or a gyro repeater.
In appearance and use, a pelorus resembles a compass or compass repeater, with sighting vains or a sighting telescope attached, but it has no directive properties. That is, it remains at any relative direction to which it is set. It is generally used by setting 000° at the lubber's line.