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Commercial vessels · Clean-air grants

Commercial Marine Engine Replacement & Grant Support

A cleaner engine. A more affordable path forward. We help owners of eligible vessels explore California’s Carl Moyer Program, which may offset part of the cost of cleaner engines, including qualifying installation labor.

Tell Us About Your Vessel Call (323) 552-7771
Technician working on an open marine diesel engine block
Waiting for the next South Coast AQMD application round

South Coast AQMD’s last round closed on July 15, 2025, and we are waiting for the next date and release. You can start now by getting your vessel and engine information ready, so you can move quickly when a round opens.

How we help

Technical planning and installation, together

Replacing an aging marine engine is a major investment. We help you understand the project before you move forward.

  1. Project assessmentWe review your vessel’s use, existing engines and operating location to identify possible funding.
  2. Replacement planWe prepare a proposal with itemized equipment, parts and installation costs.
  3. Application supportWe help organize the specifications, estimates and project details for the owner’s application.
  4. Professional installationWe complete the approved replacement and provide documentation for required inspections and payment requests.

Could your vessel qualify?

Funding is focused on commercial vessels

Eligibility depends on vessel classification, engine specifications, operating history, emissions reductions and regulatory deadlines.

Vessels that may qualify

  • Commercial fishing boats
  • Sportfishing and for-hire charter boats
  • Excursion and passenger vessels
  • Workboats, tugs and towboats
  • Crew and supply boats, pilot boats and water taxis

What funding may cover

  • The new, cleaner engine
  • Installation labor
  • Related fuel, exhaust, cooling and wiring changes
  • A new transmission, when the engine requires it
  • Dry docking, when needed for the replacement

What it generally does not cover

  • Engine repairs, overhauls and maintenance
  • Propellers, rudders and steering systems
  • Sea trials and unrelated hull work
  • Replacing a gas engine with a diesel
  • Boats used primarily for recreation

Need repairs that are not part of a funded project? We can quote that work separately.

What to expect

Funding amounts and requirements

Up to 85% of eligible costs

Some projects have lower limits, as low as 50%. Actual awards vary and can be lower based on emissions reductions.

Owner contribution

Owners generally pay at least 15% of eligible costs, plus anything outside the approved funding.

Usage records

Applications generally use two years of engine hour or fuel records, so start gathering yours now.

Old engine scrapped

Replaced engines must be permanently destroyed. Funded projects also have reporting requirements.

Grants are awarded by local air districts, not Unlimited Props. Funding availability, eligibility and payment arrangements must be confirmed for each project. Do not purchase equipment or begin replacement work until the administering district authorizes you to proceed under its grant requirements. Unlimited Props does not guarantee funding or represent a government agency. Program details can change. See South Coast AQMD and the California Air Resources Board guidelines for official information.

Start with your vessel

Tell us what you run

Tell us where your vessel operates, how it is used and which engines you want to replace. We’ll help you assess the technical scope and the next steps toward a possible grant-supported upgrade.

(323) 552-7771 info@unlimitedpropsmgmt.com
Mon–Fri, 8am–5pm