Magnetic Compass
medium
5 models total
SOLAS-mandatory magnetic compass as independent heading reference. Required even with gyrocompass installed.
4 manufacturers · 5 models
Cassens & Plath
2
Reflecta 1
Reflector compass
· Navigation Data / Sensor
· magnetic compass
Type
Magnetic compass
Solas required
ja
Common Failures & Inspection Points
- Compass card sluggishness
- Fluid bubble formation
- Deviation table outdated
Service: German quality magnetic compass. Annual deviation check mandatory.
Spare Parts: Cassens & Plath: Ersatzteile per Hersteller-Netzwerk. Lead time: 1-4 Wochen. Backup-Systeme an Bord pflichtgemäß.
Strengths
- Robust German engineering with high mechanical reliability
- Meets mandatory SOLAS requirements for all sea‑going vessels
- Low power consumption – no electrical supply needed
- Simple, intuitive readout that requires minimal crew training
- Easy to service and calibrate during annual deviation checks
Weaknesses
- Susceptible to magnetic interference from nearby ferrous equipment
- Requires regular deviation table updates and fluid maintenance
- No electronic integration with modern bridge navigation systems
- Limited to visual readout – no digital output or alarm functions
- Potential for fluid bubble formation affecting accuracy over time
Typical Vessels:
TankerContainer shipBulk carrierGeneral cargo vesselPassenger ferryOffshore supply vessel
Certifications:
SOLAS
Decision Guide: Choose if you need a proven, low‑maintenance analog heading reference that satisfies SOLAS and works without power. Avoid if the vessel relies heavily on integrated electronic navigation, requires digital output, or operates in environments with strong magnetic disturbances.
Use Cases: Deployed as the primary heading instrument on most merchant ships and as a mandatory backup to gyrocompasses on passenger vessels; also common on offshore support vessels and training ships where simplicity and reliability are paramount.
Jupiter
Projector compass
· Navigation Data / Sensor
· projector magnetic compass
Type
Projector magnetic compass
Solas required
ja
Common Failures & Inspection Points
- Projector bulb replacement
- Compass fluid leaking
- Gimbals friction
Service: Projector compass — projects heading on bridge ceiling/repeater.
Spare Parts: Cassens & Plath: Ersatzteile per Hersteller-Netzwerk. Lead time: 1-4 Wochen. Backup-Systeme an Bord pflichtgemäß.
Strengths
- SOLAS‑approved – meets mandatory international safety requirements
- Clear, high‑contrast heading projection onto the bridge ceiling for easy visibility
- Robust mechanical design with low‑friction gimbals and sealed housing
- Integrated repeater allows simultaneous heading display at multiple stations
- Low power consumption compared with electronic gyro systems
Weaknesses
- Projector bulb has a limited service life and must be replaced periodically
- Compass fluid can leak if seals deteriorate, requiring careful maintenance
- Mechanical gimbal wear may increase friction over time, affecting accuracy
- Lacks the advanced integration features of modern electronic gyro‑compasses (e.g., automatic heading sync with ECDIS)
- Physical size and mounting requirements are larger than compact solid‑state units
Typical Vessels:
Bulk CarrierTankerContainer ShipPassenger FerryOffshore Supply Vessel
Certifications:
SOLASDNVGL Class Approval
Decision Guide: Choose if you need a proven, SOLAS‑compliant analog heading source that provides clear ceiling projection and redundancy to electronic systems. Avoid if bridge space is limited, you require full digital integration with ECDIS/auto‑pilot, or prefer a maintenance‑free solid‑state solution.
Use Cases: The Jupiter is typically installed as the primary magnetic compass on ocean‑going merchant vessels, serving both as the main heading indicator and as an independent backup to gyro‑compasses. It is especially valued on ships where regulatory compliance and reliability under harsh sea conditions are paramount.
C. Plath (Weems & Plath)
1
Merkur VZ
Compensated magnetic compass
· Navigation Data / Sensor
· compensated magnetic compass
Type
Compensated magnetic compass
Solas required
ja
Common Failures & Inspection Points
- Compensating magnet adjustment needed
- Heeling error bucket issues
- Fluid bubble
Service: Standard SOLAS compass with full compensation arrangement.
Spare Parts: C. Plath (Weems & Plath): Ersatzteile per Hersteller-Netzwerk. Lead time: 1-4 Wochen. Backup-Systeme an Bord pflichtgemäß.
Strengths
- Full deviation and heeling‑error compensation integrated in the unit
- Stable liquid‑filled bubble ensures accurate, drift‑free readings
- Robust steel housing tolerates harsh marine environments
- Mechanical operation requires no electrical power, ideal for backup use
- Certified to meet SOLAS heading‑instrument requirements
Weaknesses
- Periodic manual adjustment of compensating magnets is required
- Heeling‑error bucket can develop leaks or bubble distortion over time
- Mechanical wear of pivots may affect long‑term accuracy if not maintained
- Provides only magnetic heading; no gyro redundancy for electronic bridge systems
- Larger physical footprint compared with compact solid‑state compasses
Typical Vessels:
TankerBulk CarrierContainer ShipPassenger FerryOffshore Supply VesselGeneral Cargo Ship
Certifications:
SOLASUSCG Type Approval
Decision Guide: Choose if you need a reliable, low‑power heading source that meets SOLAS requirements and can serve as primary or backup navigation on vessels where magnetic compasses are standard. Avoid if space is at a premium, the bridge relies exclusively on integrated electronic/gyro systems, or you require a fully solid‑state instrument with no moving parts.
Use Cases: Typically installed on the main bridge as the primary heading instrument on tankers, bulk carriers and other ocean‑going vessels; also used as a redundant compass alongside gyrocompasses on passenger ships and offshore supply vessels where compliance with SOLAS is mandatory.
LILLEY & GILLIE
1
Marine Compass
Magnetic compass
· Navigation Data / Sensor
· Liquid-filled magnetic compass
Type
Magnetic compass
Solas required
ja
Common Failures & Inspection Points
- Aging design
- Fluid leak risk
- Spare parts limited
Service: Traditional British compass. Heritage brand.
Spare Parts: LILLEY & GILLIE: Ersatzteile per Hersteller-Netzwerk. Lead time: 1-4 Wochen. Backup-Systeme an Bord pflichtgemäß.
Strengths
- Proven heritage design with decades of service on merchant vessels
- Meets IMO SOLAS mandatory requirements for magnetic heading devices
- No external power needed – operates purely on Earth's magnetism
- Robust, corrosion‑resistant housing suitable for harsh marine environments
- High inherent accuracy when properly calibrated
Weaknesses
- Aging design can be less stable than modern gyro or MEMS compasses
- Risk of fluid leakage over time, requiring periodic inspection
- Spare parts and service expertise are increasingly limited
- Requires regular manual calibration and maintenance
- Limited integration with electronic bridge systems
Typical Vessels:
General cargoBulk carrierCoastal tankerFishing vesselTraining ship
Certifications:
SOLAS (IMO)
Decision Guide: Choose if you need a low‑power, standalone heading source that satisfies SOLAS and fits vessels with limited electronic integration. Avoid if the ship relies heavily on integrated bridge systems, requires high redundancy electronic navigation, or if spare‑part support for legacy magnetic compasses is a concern.
Use Cases: Commonly installed as the primary magnetic compass on small to medium merchant ships, retrofits of older vessels, and training platforms where a simple, reliable heading reference is essential.
Observator
1
Marine Compass
Magnetic compass
· Navigation Data / Sensor
· Magnetic compass
Type
Magnetic compass
Solas required
ja
Common Failures & Inspection Points
- Card sticking
- Fluid discoloration
- Bracket corrosion
Service: Dutch compass. Good quality at reasonable price.
Spare Parts: Observator: Ersatzteile per Hersteller-Netzwerk. Lead time: 1-4 Wochen. Backup-Systeme an Bord pflichtgemäß.
Strengths
- SOLAS‑compliant design required for statutory navigation equipment
- Robust mechanical construction with low maintenance needs
- No external power supply required – works independently of ship's electrical system
- Reasonably priced compared with many gyro‑compass alternatives
- Simple installation on standard compass brackets
Weaknesses
- Mechanical wear can cause card sticking or fluid discoloration over time
- Requires regular deviation checks and calibration, especially after structural changes
- Susceptible to magnetic interference from nearby ferrous equipment
- Accuracy limited to about ±1° – not suitable for high‑precision navigation alone
- Bracket corrosion reported in harsh marine environments if not protected
Typical Vessels:
Coastal cargo vesselsFishing boatsOffshore supply shipsSmall tankersGeneral purpose workboats
Certifications:
SOLAS (Chapter V) compliance
Decision Guide: Choose if you need a cost‑effective, power‑independent heading source for vessels where space and budget are limited, or as a reliable backup to electronic systems. Avoid if the vessel operates in high magnetic‑interference areas, requires sub‑degree accuracy, or relies solely on electronic navigation without redundancy.
Use Cases: Commonly installed as the primary compass on small to medium‑size commercial vessels for coastal and offshore work, and used as a statutory backup on larger ships equipped with gyro‑compasses or GNSS‑based heading systems.