Although devised in ancient times the pelorus has many applications in the modern electronic world, from collision avoidance in busy waters to celestial navigation.
On larger vessels the pelorus can be an aid to watch officers for predicting crossing situations and avoiding collisions. The instrument is also useful for checking current position, for instance, in determining the moment at which an aid to navigation is broad on the beam or measuring pairs of relative bearings which can be used to determine distance off and distance abeam of a navigational aid.
In traditional navigation the pelorus can be used to determine current position by plotting 3 bearings of known objects or checking current heading in relation to sun or stars.
The pelorus is also an invaluable tool for Compass adjusters - compass deviation can be determined by comparing compass reading to the sun's azimuth or known bearings of distant objects such as navigation aids or lighthouses.
The Autonautic pelorus consists of a gimballed suspension system comprising of a gimbal ring, weight and arrest. Mounted on the gimbal assembly is the 125mm diameter card, sun shadow pin and two sighting vanes.
The card is fully rotatable, so can be aligned with ships heading for measuring relative bearings, set to north to read absolute bearings ( azimuth) or zeroed on the first object to measure the angle between two fixed points.
The pelorus is available in two versions; boxed and bracket mount:
The boxed pelorus (TAX-00122) is stored in its plywood box by resting on two lower gimbals and folding down the aluminium sighting vanes. For operational use, the pelorus is raised to engage two upper gimbals in the box and raising the sighting vanes or installing the sun shadow vane. The plywood box size is W:210 x D:210 x H:180 mm and is finished in natural wood tones.
The bracket mount pelorus (TAX-00123) comes with two mounting plates, one to be affixed with two screws at the desired installation location, the other is fixed within the storage box for safe stowage. The pelorus can be taken from its storage box and be quickly mounted on the fixed mounting plate via a thumb screw. Additional mounting plates can be supplied if additional mounting positions are required. The plywood storage box size is W:245 x D:245 x H:140mm and is finished in natural wood tones.