Ritchie provides general compensation instructions within the instruction packets that come with most compass series. Most Ritchie compasses have internal comp rods that can correct for +/- 15° of deviation. If your compass has a considerable amount of deviation (+15°), the built-in compensators will not be enough. Hiring a professional compass adjuster may be the way to go. A professional compass adjuster is trained to help you locate potential causes of deviation and make recommendations to reduce them. Your local marina or harbor master should be able to put you in touch with a compass adjuster.
My compass worked correctly when I bought it but now that it is installed it is not reading correctly, what’s wrong?
Most likely, there is something mounted too close to the compass causing magnetic interference. Some culprits include Magnets (speakers, microphones etc.), ferrous metals (steel, iron, etc.) and current carrying devices.
The factors which cause the difference between COG and Heading have a greater affect at slow speeds. More importantly, the GPS, which uses historical data to calculate COG, needs a straight line to give an accurate reading. When you make a turn at slow speed, you will need to travel in a straight line for a period of time before the GPS can give you an accurate calculation. While a boat is at rest, there is no historical data for the GPS. Therefore, there is no COG to report. The COG given by the GPS tends to be erratic and [...]
A GPS provides COG (course over ground). COG is calculated from historical position data to give average COG. The magnetic compass gives you real-time heading for your boat. COG and Heading are both an integral part of navigation. Conditions such as wind, tide, current and even physical properties of your boat can cause differences between COG and Heading. Heading is the only reliable reference to steer your vessel accurately under all conditions. Check out our Resource Center for additional information.
It may seem like the compass is 180 degrees off depending on what style dial you are accustomed to reading. We manufacture compasses with 3 different types of dial styles – Open face (flat card), Direct read, and Combi. Most are familiar or used to reading traditional “Flat card compasses”. To read a flat card compass, you look down at the compass card and read the heading at the lubberline (pointer) farthest away from you. A “Direct reading compass”: A direct read compass is read at/around eye level. You look at the front of the compass and read the heading [...]
Until 2001, all Ritchie compasses (see exception) were filled with Odorless Mineral Spirits (100% Paraffin based). Ritchie now uses a fluid called Isopar L that has similar properties but some added benefits over Odorless Mineral Spirits. Exception: Some old style Flat Top Compasses used a mix of denatured alcohol and water. This process was stopped in the 1960s. If you have a Flat Top Compass, it is recommended that you test the fluid to see if it is Odorless Mineral Spirits or an alcohol/water mix.