Marine Service, Support, & Sales
Spanning the U.S. coastline from the Atlantic Coast to Florida and the Texas Gulf Coast, we serve as a premier authorized distributor with deep technical expertise and a legacy of reliability. We provide precision diesel engine sales, genuine OEM parts, and expert repower management tailored to the specific demands of your vessel. Whether maintaining the rigorous schedules of commercial ferries and offshore transport vehicles or ensuring the peak performance of luxury motor yachts and sportfishing boats, our factory-certified technicians are ready to deploy. From new commissions to emergency dockside repairs, we deliver the power and support that keeps you moving.
Workboat
Yacht
Sportfishing
Marine Service
Warranty-safe service and maintenance for commercial and recreational vessels, dockside, in yard, or on the water.
Our technicians provide expert diagnostics, maintenance, and repair for marine diesel engines, including VM Motori, with OEM-backed parts and service.
Preventive Maintenance & Inspections
Comprehensive preventive maintenance programs designed to reduce downtime, extend engine life, and support reliable vessel operation.
OEM & Quality Aftermarket Parts
We stock genuine OEM and approved aftermarket parts for exact fit, performance, and fast turnaround, protecting reliability and warranty coverage.
Mobile Field Service & Dockside Support
Our mobile technicians provide on-site diagnostics, emergency repairs, and service support at marinas, shipyards, and operating locations.
Diagnostics & Troubleshooting
Advanced diagnostic tools and OEM procedures allow our technicians to quickly identify issues and restore engine performance efficiently.
Warranty & Authorized Service
As an authorized service provider, we perform warranty and post-warranty repairs in accordance with mtu and Volvo Penta standards.
Marine Support
Locations & Service Coverage
Marine service is supported through a coordinated network of Stewart & Stevenson locations across Texas and the Gulf Coast, supplemented by our sister companies Florida Detroit Diesel Allison (covering Florida and the Southeast) and Atlantic Detroit Diesel Allison (covering the Northeast coast and Mid-Atlantic markets). This integrated network ensures that whether your vessels operate out of Texas ports, Gulf Coast waterways, Florida marinas, or Northeast harbors, a certified technician with the right OEM tools and marine engine parts is positioned to respond quickly.
Vessels We Serve
Commercial Vessels:
- Tugboats and push boats
- Passenger ferries and dinner cruisers
- Offshore wind farm support vessels
- Pilot boats
- Auxiliary vessels and barges
- Parasail and charter boats
- Naval patrol crafts
- Coast Guard vessels
Pleasure Craft:
- Sportfishing yachts
- Motor yachts
- Sailing yachts
Marine Engine Repower
Extend Vessel Life. Improve Performance. Reduce Operating Costs.
When your engines can no longer meet the demands of your schedule, or the rigors of modern emissions standards, a repower is the most cost-effective way to modernize your fleet. By integrating the latest mtu marine engines or Volvo Penta technology into your existing hull, Stewart & Stevenson delivers increased uptime, lower fuel costs, and a total restoration of reliability to your vessel.
Why Consider Repowering?
- Chronic downtime or increasingly unreliable engine performance
- Obsolescence and escalating difficulty sourcing genuine OEM parts
- Rising fuel consumption and operating costs that reduce margins
- Emissions or regulatory compliance concerns (EPA Tier 4 / IMO Tier III)
- Need for increased horsepower, torque, or propulsion efficiency
- Approaching end-of-life for legacy engine platforms with limited support
Our Marine Repower Approach
We manage the entire repower process from start to finish:
Evaluate
vessel condition, operating profile, and duty-cycle requirements
Recommend
the most suitable Volvo Penta or mtu engine solution
Coordinate
installation planning and execution with yards and partners
Commission
and validate full system performance to OEM specifications
Provide
ongoing marine diesel engine service, warranty support, and genuine parts after installation
Marine Engine Sales
Marine
“Impeccable customer service from Dakota in the service center and top notch work from shop! My first pick for repairs in mid and south Florida!”
Joshua Hathaway
Genuine Oem Marine Engine Parts to
Keep Your Vessel Running
Stewart & Stevenson provides genuine mtu and Volvo Penta marine parts backed by expert support and efficient logistics. From routine maintenance items to critical components, our parts teams help minimize downtime and protect long-term engine performance.
FAQs
Yes. Stewart & Stevenson FDDA LLC and Stewart & Stevenson ADDA are certified mtu marine and factory-authorized Volvo Penta marine dealers. Throughout our service territories, we provide marine propulsion engines, comprehensive diesel service, expert repower project management, and genuine OEM parts. Our factory-authorized status guarantees that all work meets strict manufacturer standards, preserves your warranty coverage, and ensures direct access to the complete OEM parts pipeline.
What types of vessels do you support?
We support a wide range of commercial vessels and pleasure craft, including tugboats and push boats, passenger ferries and dinner cruisers, offshore support and wind farm vessels, pilot boats, barges, and parasail boats. On the recreational side, we service sportfishing yachts, motor yachts, and sailing yachts. If your vessel runs on a mtu or Volvo Penta engine, our certified technicians have the tools, training, and marine engine parts to support it. We also service other makes and models of marine engines.
Do you provide dockside and field service?
Yes. Our marine service teams offer dockside marine service, in-yard maintenance, and full mobile field service, depending on your vessel’s location and service requirements. Our mobile technicians are deployed with OEM diagnostic tools and stocked parts inventories and are available across the Gulf Coast, Texas, Florida, and Northeast service areas to support both scheduled maintenance programs and urgent repair situations.
When should I consider repowering instead of repairing?
You should seriously evaluate a marine engine repower when the cumulative cost of maintaining aging hardware — including escalating repair frequency, rising fuel consumption, and lost revenue from unplanned downtime — no longer justifies continued investment in a legacy system. Additional triggers include difficulty sourcing genuine OEM parts, emissions compliance requirements (EPA Tier 4 / IMO Tier III), and the need for increased power or torque.
