Boat owner’s guide

Compass Check List

Simple checks you can do yourself before, during and after a trip. If anything fails, call a professional adjuster.

Tick items off as you go. Nothing is saved or sent.

At the DockBefore you leave

Check alignment with the boat’s centerline A-coefficient
Pedestal-mounted (sail) or centerline-mounted: sight the compass center pivot pin, the forward lubber line, and the mast or bow. All three should line up. If not, slew the compass until they do.
Watch the gauges near the compass
If ammeters, tachometers or other gauges sit near the compass, watch the card while you change engine RPM. Does the heading move? If yes, consult a professional.
Clear the 8-foot zone
Look within 8 feet of the compass in every direction for loose iron and steel: anchors, stereo speakers, propane tanks, air horns and handheld VHF radios. Secure everything in the same place every trip.

Under WayCheck against fixed land ranges

North / South headings C-coefficient
Run a fixed land range close to north or south and compare your compass heading. It should be within ±10°.
East / West headings B-coefficient
Run a fixed land range close to east or west and compare your compass heading. It should be within ±10°.

Why fixed ranges, not GPS or buoys?

Fixed land ranges never move. Floating aids to navigation can drag off station. GPS and Loran show a “has-been” reading, an average of where you have been (say 162° at 6.2 knots), not where you are pointing right now. Even holding a steady course for several minutes won’t match the accuracy of a fixed land range.

After the VoyageProtect the dome

Rinse with fresh water
Compasses love fresh water baths. Don’t wipe salt spray off the dome with your hand, because it dulls the plastic. Never use abrasive cleaners or wax on the dome.
Cover it up
Keep the compass covered whenever the boat isn’t in use. A light-colored cover reflects the UV rays that cause crazing on the plastic dome.

Failed a check?

We’ll swing and adjust your compass at your dock, in any weather.

Call 410-626-9892 Email Us