Bridge Magnetic Compass Deviation Log & Residual Error Table
Standard observation protocol for bridge watchkeeping officers to monitor residual deviation against the valid Deviation Card.
Vessel Name:
IMO Number:
Compass Make / Serial:
Date of Last Swing:
Ship's Head (Magnetic)
Ship's Head (Gyro)
Gyro Error (High/Low)
True Heading
Observed Variation
Calculated Deviation
Deviation Card Value
Delta (Residual Error)
000° (N)
045° (NE)
090° (E)
135° (SE)
180° (S)
225° (SW)
270° (W)
315° (NW)
Statutory Re-Swinging Mandate (SOLAS V / 19.2.1 & DGS Engineering Circulars):
Compass adjustment and issuance of a new Deviation Card by a MCA Approved Compass Adjusters is mandatory:
1. Annually or immediately following drydocking / major structural steel repairs / hot work within 5m of binnacle.
2. If residual deviations exceed 3° on any cardinal heading during routine sea passage observations.
3. Following discharge of electromagnetic or high-permeability cargo (iron ore, steel coils, heavy scrap).