DA Form 5073: Magnetic Compass Deviation Table (PDF) – Magnetic compasses remain essential backup navigation tools on U.S. Army watercraft, even with modern GPS and gyro systems. DA Form 5073, officially titled Magnetic Compass Deviation Table, records compass deviations for safe and accurate navigation. This form supports compliance with AR 56-9 (Watercraft Operations) and ensures Army vessels meet navigational safety standards.
Download the official DA Form 5073 PDF here: https://armypubs.army.mil/pub/eforms/DR_a/pdf/A5073.pdf
What Is DA Form 5073?
DA Form 5073 is a standardized U.S. Army document used to create and maintain a magnetic compass deviation table for vessels. It records the difference (deviation) between the compass reading and the actual magnetic heading on various ship’s headings.
The form applies primarily to Army watercraft operations under the Department of the Army. It includes sections for:
- Vessel and compass identification (make, serial number, binnacle type)
- Deviation values for headings in 15° increments (0° to 345°)
- Details on adjustments (magnets, spheres, heeling magnet, etc.)
- Signatures from the adjuster/navigator and master
- Location information (e.g., Pilot House, Secondary Conning House)
This table helps mariners correct compass readings for safe course plotting and steering.
Why Magnetic Compass Deviation Matters in Army Watercraft?
Deviation occurs due to the vessel’s own magnetic influences—steel hull, engines, electronics, cargo, and equipment. Unlike variation (Earth’s magnetic field difference from true north), deviation varies by heading and changes with modifications to the vessel.
Accurate deviation records are critical because:
- They enable correction from compass headings to magnetic (and true) headings.
- U.S. regulations (e.g., 33 CFR 164) and Army policy require a current deviation table or record for the steering compass.
- They support safe navigation during GPS/gyro failures, low visibility, or electronic interference.
- AR 56-9 mandates an accurate DA Form 5073 posted on the vessel, with hourly compass comparisons while underway.
Failure to maintain this can compromise safety and regulatory compliance for Army vessels operating on inland waterways or oceans.
When to Complete or Update DA Form 5073?
Update the form in these situations (aligned with Army and maritime standards):
- After initial compass installation or adjustment.
- Following structural changes, dry docking, or major equipment modifications.
- When deviations become excessive or records are incomplete.
- Periodically (e.g., annually or as required by vessel class and operations).
- After any event that could affect the vessel’s magnetic signature.
Army watercraft masters and mates ensure the table remains current as part of pre-departure checks.
How to Fill Out DA Form 5073: Step-by-Step Guide?
- Identify the Compass: Enter make, serial number, binnacle type (e.g., Navy Standard), and location (Pilot House, etc.).
- Swing the Ship: Steer the vessel on multiple headings (typically every 15°) and compare the compass reading to a known accurate magnetic reference (e.g., sun’s azimuth, gyro, or shore bearings).
- Record Deviations: Note the deviation (East or West) for each heading in the table.
- Document Adjustments: Record details of corrective magnets, spheres, Flinders bar, heeling magnet, and any cyclic error.
- Sign and Approve: The adjuster/navigator and master sign the form.
- Post the Form: Keep the completed table readily available near the compass.
Pro Tip: Perform the swing in calm conditions with minimal external magnetic interference for best accuracy.
Best Practices for Magnetic Compass Maintenance on U.S. Army Vessels
- Conduct regular comparisons between magnetic and gyro compasses.
- Post the current DA Form 5073 visibly in the wheelhouse.
- Train crew on deviation corrections and compass use.
- Combine with other navigation tools for redundancy.
- Follow TM 55-500 and other watercraft technical manuals for detailed procedures.
Proper maintenance ensures compliance with both Army regulations and broader U.S. Coast Guard/IMO-inspired standards for vessels.
Common Questions About DA Form 5073
Who uses DA Form 5073?
Army vessel masters, mates, navigators, and compass adjusters for watercraft operations.
Is it the same as Navy or commercial forms?
Similar in purpose, but this is the specific DA form prescribed by AR 56-9 for Army use.
Where to get the latest version?
Direct from Army Publishing Directorate: Download DA Form 5073. Previous editions are obsolete.
Conclusion: Ensure Navigational Readiness with DA Form 5073
DA Form 5073 is more than paperwork—it is a vital safety tool that supports mission success and crew safety for U.S. Army watercraft operators across the nation. Keeping your magnetic compass deviation table accurate and up-to-date demonstrates professionalism and regulatory compliance.
For official guidance, consult AR 56-9 and your unit’s marine safety officer. Always use the latest form from armypubs.army.mil.
Keywords: DA Form 5073, Magnetic Compass Deviation Table, Army watercraft navigation, AR 56-9, compass adjustment, US Army vessels.