SPEED LOG
A Speed Log is a navigation device used on ships to measure the vessel’s speed through water and distance travelled. This information is essential for the bridge team to monitor the vessel’s movement and maintain safe navigation during voyages. Speed log data is commonly integrated with other bridge systems such as ECDIS, Autopilot, and Voyage Data Recorder, allowing the ship’s navigation systems to operate efficiently and accurately.
Need Speed Log Installation, Repair, or Supply?
If your vessel requires Speed Log installation, maintenance, troubleshooting, or equipment supply, our team is ready to assist. We provide professional Speed Log service for ships across UAE ports and worldwide shipping routes, ensuring your navigation equipment remains accurate, reliable, and fully operational.
Contact us today to schedule service support or request a quotation for your vessel.
Types of Speed Logs Used on Ships
Modern vessels generally use two main types of speed log systems:
Doppler Speed Log (DSL)
Uses Doppler frequency shift technology to measure the vessel’s speed relative to the seabed or water mass.
Electromagnetic Speed Log (EM Log)
Measures speed through water using electromagnetic sensors installed on the ship’s hull.
Both systems provide reliable speed data for navigation monitoring, voyage planning, and performance tracking.
Common Speed Log Issues on Ships
Speed log systems may experience issues due to sensor fouling, electrical faults, or system errors. Common problems include:
Incorrect speed readings
No speed data displayed on the bridge
Sensor malfunction or hull unit damage
Data not transmitted to ECDIS or other bridge equipment
Alarm or system failure
Our technical team can quickly diagnose and resolve these issues, minimizing vessel downtime.
Our Speed Log Technical Services
Our marine engineers provide complete Speed Log technical support for vessels operating in UAE ports and international waters, including:
Speed Log installation and system commissioning
Fault finding and troubleshooting
Sensor inspection and hull unit maintenance
Calibration and accuracy testing
Repair of display units and processing units
Supply of new Speed Log systems and spare parts
Integration with bridge navigation systems
We ensure the equipment operates with maximum reliability and precision during vessel operations.
Why Choose Our Speed Log Services
Experienced marine navigation engineers
Support across UAE ports and international routes
Fast onboard troubleshooting and repair
Supply of reliable marine navigation equipment
Professional service aligned with marine industry standards
We focus on delivering safe, accurate, and dependable navigation equipment solutions for vessels.
What is a speed log?
A Speed Log is a vital navigational instrument that measures a vessel’s speed through water using Doppler shift or other precision methods, supporting safe navigation and efficient voyage planning.
What are the types of speed logs?
Common types of speed logs include Doppler Speed Logs, Electromagnetic Speed Logs, and Acoustic Doppler Current Profilers (ADCPs). Each system employs specific measurement principles to provide accurate and reliable vessel speed data for safe navigation and precise voyage planning.
How does a speed log work?
Speed Logs typically utilize Doppler technology to determine a vessel’s speed through water. The system emits acoustic signals that reflect off suspended particles, and the frequency shift of the returning echoes is analyzed to calculate accurate water-relative speed, essential for safe navigation and precise voyage management.
What units are used to measure vessel speed?
Speed Logs measure a vessel’s speed in knots (nautical miles per hour), the standard unit of speed in maritime navigation, providing accurate data for safe maneuvering, voyage planning, and performance monitoring.
Where are speed logs installed on a vessel?
Speed Logs are typically mounted on the vessel’s hull, below the waterline, to accurately measure the flow of water past the ship, providing precise speed data essential for safe navigation and efficient voyage operations.
Are speed logs affected by sea conditions?
Yes, sea conditions including waves, currents, and variations in water density can impact the accuracy of speed logs. Periodic calibration and adjustments are essential to compensate for these environmental factors and ensure precise speed measurements for safe navigation.
Can speed logs measure speed over ground?
No, speed logs measure the vessel’s speed through water (water speed), while Speed Over Ground (SOG) is determined using GPS (Global Positioning System) devices. Both readings are essential for accurate navigation and voyage planning.
What are the benefits of using a speed log?
Speed logs deliver real-time vessel speed data, essential for safe navigation, collision avoidance, accurate fuel consumption calculations, and compliance with international maritime regulations.
How accurate are speed logs?
Modern speed logs offer high-precision measurements, with minimal margin of error, ensuring safe navigation, accurate maneuvering, and reliable performance monitoring for vessels.
How often should a speed log be calibrated?
Speed logs must be calibrated regularly in accordance with manufacturer guidelines and regulatory requirements to ensure accuracy, reliability, and optimal performance for safe navigation.
Conclusion
Speed logs are critical navigational instruments that accurately measure a vessel’s speed through water, supporting safe navigation and operational efficiency. Utilizing advanced technologies such as Doppler and electromagnetic principles, speed logs provide precise data that enhance maritime safety, maneuvering, and overall vessel performance.
Aramaic International Marine Service
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A reliable NavCom solutions provider with an established presence across the UAE, ASIA, EUROPE and AFRICA offering advanced marine navigation and communication systems that ensure vessels remain fully connected, SOLAS-compliant, and operationally efficient across global trade routes.