Description
Diagnose, maintain, repair, and overhaul marine diesel engines and related propulsion and auxiliary systems on boats and ships. Perform troubleshooting, preventive maintenance, component rebuilds, and alignments, with dock or sea-trial verification to ensure safe, reliable, and compliant vessel operation.
- • Use hand and power tools, precision gauges, and lifting gear to service marine engines and equipment.
- • Inspect steering systems, propulsion components, and shaft bearings for proper operation.
- • Perform routine maintenance, including oil and filter changes, coolant service, fuel filtration, and lubrication.
- • Align engines and shafts, adjust controls and linkages, tighten hardware, and reassemble components.
- • Lift engines, gearboxes, and heavy parts using hoists, cranes, or gantries.
- • Conduct dock and sea trials to diagnose issues and verify repairs.
- • Diagnose faults by inspecting, testing, and listening, using scan tools, analyzers, and pressure or vacuum gauges.
- • Check guards, clamps, hoses, seacocks, and safety devices; adjust or replace as needed.
- • Measure dimensions and clearances to confirm manufacturer specifications.
- • Service and calibrate fuel injection and high-pressure common-rail systems.
- • Attach test instruments and read dials, gauges, and diagnostic software to identify malfunctions.
- • Service and rewire starting and charging systems, navigation lights, and instrument panels.
- • Recondition or replace pistons, bearings, gears, valves, pumps, and related parts.
- • Inspect, repair, and maintain bilge, seawater, and fire pumps; compressors and hydraulic systems.
- • Disassemble and overhaul marine diesel engines, generators, reduction gears, and clutches.
- • Rebuild and repower marine diesel engines and generator sets.
- • Align engine mounts, couplings, struts, and propeller shafts.
- • Diagnose and repair raw-water and closed-loop cooling systems, heat exchangers, and exhausts.
- • Troubleshoot and repair electronic engine controls and emissions aftertreatment to meet marine regulations.
- • Follow environmental best practices for spill prevention, waste handling, and resource conservation.
- • Maintain or repair vessels with alternative propulsion or fuels, including hybrid-electric or biodiesel systems.
- • Perform emissions checks or tune engines to meet EPA or IMO marine standards.
- • Install or repair marine accessories, gauges, controls, and auxiliary equipment.
- • Repair or adjust hatches, doors, windows, and deck hardware.
- • Service propellers, shafts, cutless bearings, and shaft seals; remove and install as required.
- • Grind and reset valves using valve-refacing equipment.
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Tasks & skills:
O*NET occupational data (work activities, skills, knowledge).
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This site includes information from O*NET by the U.S. Department of Labor, Employment and Training Administration (USDOL/ETA), used under the CC BY 4.0 license. Career Clutch has modified some of this information for student readability. USDOL/ETA has not approved, endorsed, or tested these modifications. O*NET® is a trademark of USDOL/ETA.
Last reviewed: Jan 2026
