Marine Generators, Gears and Engines
Marine diesel engines and generators are the primary power source for every vessel and offshore platform that operates beyond the reach of the utility grid. Whether you're outfitting a commercial fishing vessel, a tug, a barge, a cargo ship, or an offshore drilling platform, the right marine power unit determines your operational reliability, fuel efficiency, and uptime.
Depco Power Systems stocks new, rebuilt, and used marine diesel engines and marine generators sourced from the world's most trusted manufacturers, including Caterpillar, Cummins, Detroit Diesel, John Deere Marine, Volvo Penta, and MTU. Our Houston-based facility has served commercial marine and offshore operators across the Gulf of Mexico and beyond for decades, and we carry units ready to ship today.
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Offshore and Marine Operations
Using marine generators and engines is the only way to operate on the water. All power needed to operate ships, vessels, and equipment requires a marine engine or a marine generator. Because of the unique operating conditions, all engines and generators must be certified for marine use. Marine engines and generators have unique specifications that tolerate a wet environment and resist corrosion, including:
- Non-corrosive material, like stainless steel
- Water-cooled, instead of air-cooled
- Flame arrestor to reduce fire risk
- Many configurations to fit varied uses
- Compact design
Marine engines and generators are purpose-built for the harsh demands of saltwater environments. Unlike standard industrial units, certified marine engines must meet design standards set by classification societies including ABS (American Bureau of Shipping), DNV (Det Norske Veritas), and Lloyd's Register. These certifications cover corrosion resistance, fire suppression, vibration tolerance, and redundant cooling systems.
Key specifications to consider when selecting a marine power unit:
- Power output: Marine generators typically range from 20 kW for small recreational or light commercial vessels up to 3,000 kW or more for large offshore platforms and FPSOs.
- Engine type: Most commercial marine applications rely on diesel engines for their fuel efficiency and reliability at continuous load. Common marine diesel engine models include the Caterpillar 3412, 3508, 3512, 3516, C18, and C32; Cummins KTA19, KTA38, and QSK series; and Detroit Diesel 12V71 and 16V92 series.
- Configuration: Marine generator sets can be configured as standalone gensets, packaged with marine switchgear, or supplied as matched engine-transmission sets for propulsion applications.
- Cooling: Marine engines use raw water, keel cooling, or heat exchanger systems. Confirm your vessel's cooling infrastructure before specifying a unit.
Depco's team can help you match power output, duty cycle, and footprint to your vessel or platform requirements. We either have it in stock or know where to source it fast.
Browse Our Inventory of Marine Generators and Engines
Marine and Offshore Applications We Serve
Depco supplies marine engines and generators across a wide range of commercial and industrial applications on and offshore:
- Commercial fishing vessels: Reliable propulsion and auxiliary power for long-haul trawlers, shrimp boats, and processing vessels operating in demanding ocean conditions.
- Tugboats and push boats: High-torque diesel engines for inland waterway and harbor tug applications, including twin-screw configurations.
- Barges and work boats: Auxiliary generator sets for crane barges, derrick barges, cable-lay vessels, and offshore supply vessels (OSVs).
- Offshore oil and gas: Generator sets and diesel engines for drilling rigs, jack-up platforms, semisubmersibles, and fixed production platforms in the Gulf of Mexico and beyond.
- Subsea and ROV support: Power generation equipment for vessels supporting remotely operated vehicles (ROVs) and subsea installation work.
- Port operations: Shore power and auxiliary diesel generators for marine terminals, shipyards, and dry docks.
- Merchant shipping and cargo: Replacement and spare marine diesel engines for bulk carriers, container ships, tankers, and ro-ro vessels.
Frequently Asked Questions: Marine Diesel Engines & Generators
What is a marine diesel generator?
A marine diesel generator is a generator set specifically designed and certified for use on vessels and offshore platforms. It pairs a diesel engine with an alternator to produce electrical power onboard. Unlike standard industrial gensets, marine generators are built with corrosion-resistant materials (typically stainless steel hardware and marine-grade coatings), water-cooled systems, and flame arrestors to meet the safety requirements of a saltwater environment. They must be certified by a classification society such as ABS, DNV, or Lloyd's Register before installation on a commercial vessel.
What is an offshore generator?
An offshore generator is a generator set deployed on an offshore structure, such as an oil and gas drilling rig, a production platform, a floating production storage and offloading unit (FPSO), or a subsea support vessel to supply electrical power for drilling equipment, safety systems, accommodation modules, and processing facilities. Offshore generators operate continuously at high load and must meet strict reliability and safety standards given the remoteness of offshore operations.
What are the best marine diesel engine brands?
The most widely used commercial marine diesel engine brands include Caterpillar (3400, 3500, and C-series), Cummins (KTA and QSK series), Detroit Diesel (Series 71 and 92 two-strokes, and Series 60 four-strokes), John Deere Marine, Volvo Penta, and MTU. The right brand depends on your vessel type, power requirements, available parts support in your operating region, and budget. Depco carries units from all of these manufacturers in new, rebuilt, and used condition.
What is the difference between a marine engine and a marine generator?
A marine engine (or marine propulsion engine) is used to drive a vessel's propeller shaft, moving the boat through the water. A marine generator (or genset) is used to produce electrical power for onboard systems like lighting, navigation, pumps, deck machinery, HVAC, and electronics. Many larger commercial vessels have separate propulsion engines and generator sets. Some configurations use a shaft generator that draws power from the propulsion engine to generate electricity. Depco supplies both marine propulsion engines and standalone marine generator sets.
Can I use a standard diesel generator on a boat or offshore platform?
No. Standard industrial or standby generators are not suitable for marine or offshore use. They lack the corrosion-resistant construction, marine-rated ignition protection, and certifications required by classification societies. Using a non-certified generator on a commercial vessel can result in insurance voidance, port state control violations, and serious safety hazards. All commercial marine and offshore power equipment must carry the appropriate class certification for its application.
Does Depco sell used and rebuilt marine engines?
Yes. Depco stocks new surplus, professionally rebuilt, and used marine diesel engines and generator sets. All used equipment is inspected and documented before listing. Rebuilt units are reconditioned to meet or exceed OEM specifications. We provide detailed condition reports, hours, and maintenance history where available. Browse our current marine inventory or contact our sales team for units not currently listed online.
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