Ritchie Explorer marine compass with a 70 mm compass card is a magnetic steering compass for powerboats. This B-51W variant features a white housing, white card, and an adjustable mounting bracket, which allows the compass to be adjusted to the desired viewing angle.
The direct-reading card is designed for front reading and has 5° graduations. The compass is liquid-damped and equipped with DirectiveForce magnets that contribute to rapid stabilization on course. The magnet mechanism utilizes a matched sapphire jewel bearing and a hardened steel pivot, while built-in compensators are used to correct for fixed deviation.
The housing is manufactured from temperature-resistant composite material. The factory-sealed capsule is protected by a movable sun shield, which can be positioned according to lighting conditions. The compass is designed to be serviceable, and the manufacturer's warranty against defects in materials and workmanship is 5 years. A protective cover is not included.
The detachable bracket can be mounted on a deck or instrument panel. The compass is secured with two thumb screws and can be tilted forward or backward in the bracket. The total width is 116 mm, and the height including the bracket is 119 mm. The mounting surface must be level across, and the compass must be placed parallel to the boat's centerline.
The mounting location must be checked for magnetic interference from, among other things, speakers, steel and iron parts, current-carrying cables, windshield wipers, and other electrical equipment. Variable magnetic fields cannot be removed with the compensators. Use non-magnetic fasteners and choose a mounting location where the deviation does not exceed 15° on the four cardinal headings.
The internal green night lighting connects to 12 V DC. The lighting should be connected to a suitably fused circuit; for a separate circuit to the compass, a 1 A fast-acting AGC glass fuse is recommended. Check the wire markings and polarity on the supplied cable before connection.
Rinse salt and dirt off with clean fresh water and wipe the compass gently with a damp cloth. Do not use chemical or abrasive cleaning agents. Deviation should be checked at the beginning of each sailing season and after installing new equipment nearby. Checking and recording every 30° heading provides a better overview of the accuracy on all headings.
Spare parts and cross-references
The manufacturer model is B-51W. B-51W-CLM and B-51WCLM are used as secondary cross-references. Documented spare parts include white sun shield EX-0121, white compass unit EX-0124 ASY, white housing EX-0123, white bracket EX-0177 XSP, white thumb screws EX-0173 XSP, and 12 V light and wire assembly EX-0022 ASY.
Key featuresMagnetic marine compass for powerboats
70 mm direct-reading compass card with 5° graduations
White housing and white card
Adjustable and detachable mounting bracket
Built-in compensators for fixed deviation
DirectiveForce magnets and liquid-damped capsule
Green 12 V night lighting
Movable sun shield
116 mm wide and 119 mm high including bracket
Manufacturer model B-51W
