User Manual for Silva 125B/H Marine Compass

Quick guide from the manual

The Silva 125B/H is a marine compass designed for sailing boats and motor yachts. Key setup steps include ensuring the unit is mounted at a right angle to the boat's longitudinal direction and performing magnetic compensation if deviation exceeds 5 degrees. Always check for magnetic interference from nearby electronics or iron objects before final installation.

Product Overview

The package includes the compass unit, illumination, and a mounting kit. The compass features a built-in clinometer (+/- 45 degrees), a yellow main lubber line, and two yellow aid lines at 45 degrees.

Positioning and Mounting

The compass should be positioned where it can be easily read from all angles, even in darkness when illuminated. It is intended for flush mounting.

• Positioning: Mount vertically or sloping (max 30 degrees). If a compensator is fitted, it must be mounted vertically.
• Magnetic Interference: Position as far as possible from iron objects, speakers, windscreen wipers, and other magnetic sources. Use a handheld compass to check for interference.
• Mounting: The compass must be mounted exactly at right angles to the boat's longitudinal direction. Use the enclosed template to drill the hole. Ensure correct mounting depth to avoid damaging the expansion membrane, which could lead to leakage.
• Installation: For the 125B/H model, loosen the four outer screws at the back, remove the compass from the front plate, mount the front plate to the bulkhead, and screw the compass on from the inside.

Compensation and Deviation

Compensation is recommended if the deviation is more than 5 degrees. If the error is less than 5 degrees, it is sufficient to produce a deviation table.

1. Aim the boat due North and turn the N/S screw until the reading is 0 degrees.
2. Aim the boat due East and turn the E/W screw until the reading is 90 degrees.
3. Aim the boat due South. If the reading is not 180 degrees, turn the N/S screw until the error is halved.
4. Aim the boat due West. If the reading is not 270 degrees, turn the E/W screw until the error is halved.
5. Repeat the procedure to check adjusted values.
6. Check the compass every 20 degrees to produce a deviation table and curve.

Maintenance

Clean the compass using a mild soap solution or detergent. Do not use strong solvents such as spirit, acetone, or petroleum. The compass tolerates temperatures down to -30 degrees Celsius, but it is advisable not to subject it to severe cold for long periods.

Technical Specifications

• Illumination: 12V, red color.
• Accuracy: +/- 0.5 degrees.
• Apparent card diameter: 125 mm.
• Operating temperature: -10 degrees Celsius to +70 degrees Celsius.
• Weight: 1300 g.