Marine Lubricants and Greases

Supporting Marine Engines and Onboard Systems

Correct lubrication is essential to maintain reliable performance and protect equipment operating in wet, humid and potentially corrosive environments.

Rock Oil products are designed to help:

• Protect engines and mechanical components against wear.
• Support reliable performance under sustained loads.
• Resist corrosion, oxidation and lubricant breakdown.
• Maintain smooth steering, transmission and gear operation.
• Protect equipment exposed to moisture and saltwater.
• Support routine servicing, storage and recommissioning.

Marine Engine Oils

Rock Oil supplies dedicated engine oils for a broad range of marine applications, including leisure craft, personal watercraft and commercial vessels.

The range includes products for:

• Two-stroke outboard engines.
• Four-stroke outboard engines.
• Petrol and diesel inboard engines.
• Direct-injection and conventional two-stroke systems.
• Injector and premix applications.
• Medium- and high-speed marine diesel engines.
• Personal watercraft and specialist high-performance applications.

Synthetic, semi-synthetic, mineral and biodegradable options are available across the range, allowing the lubricant to be matched to the engine technology, operating conditions and manufacturer’s requirements.

NMMA-Certified Marine Lubricants

Selected Rock Oil marine products carry certification from the National Marine Manufacturers Association.

The range includes products meeting:

• NMMA TC-W3® requirements for selected two-stroke marine engines.
• NMMA FC-W® requirements for selected four-stroke marine engines.
• NMMA FC-W Catalyst Compatible® requirements for engines fitted with relevant emissions systems.

These certifications provide reassurance that the lubricant has been developed and tested around the particular demands of marine engine operation.

The engine manufacturer’s stated oil type, viscosity and performance standard should always be checked before selecting a product.

Steering, Transmission and Gear Lubricants

Marine steering, transmission and gear systems rely on the correct fluids to maintain smooth operation and protect internal components.

Rock Oil supplies products for:

• Hydraulic steering systems.
• Power-steering and transmission applications.
• Marine gear drives.
• Extreme-pressure gear systems.
• Associated mechanical and driveline components.

These lubricants are designed to support wear protection, responsive operation and dependable performance under load.

Because system requirements vary considerably between vessels and manufacturers, each product should be matched carefully to the stated specification.

Marine Greases

Marine greases must maintain their protective film while exposed to water, salt, vibration and changing loads.

Rock Oil offers specialist greases for applications including:

• Stern tubes.
• Bearings.
• Bushes and joints.
• Linkages.
• General marine components.
• Machinery exposed to water wash-off.
• Heavily loaded and adhesive lubrication points.

Available technologies include water-resistant calcium, aluminium-complex and semi-synthetic greases developed to provide corrosion protection, adhesion and dependable lubrication in wet environments.

Coolants and Antifreeze

The KOOL-GUARD range provides coolant and antifreeze solutions for marine engines and associated cooling systems.

The portfolio includes:

• Conventional coolant technologies.
• Organic Acid Technology formulations.
• Silicated OAT products.
• Ethylene glycol-based options.
• Propylene glycol-based marine coolants.
• Concentrated and ready-to-use products.

These products are designed to help:

• Protect against freezing and overheating.
• Control cooling-system corrosion.
• Maintain efficient heat transfer.
• Protect mixed-metal cooling systems.
• Support reliable year-round operation.

The correct coolant technology should always be selected according to the engine manufacturer’s requirements, and different coolant types should not be mixed unless compatibility has been confirmed.

Corrosion Protection and Maintenance Products

Marine equipment is continually exposed to moisture, salt and atmospheric corrosion.

Rock Oil supplies maintenance products for:

• Water displacement.
• Corrosion prevention.
• Cleaning and degreasing.
• Penetrating seized components.
• Lubricating hinges, cables, chains and linkages.
• Protecting wire ropes and open gears.
• Applying anti-seize protection.
• Routine onboard and workshop servicing.

These products provide practical support for leisure vessels, commercial fleets, boatyards and marine workshops, helping protect exposed components during both operation and storage.

Supporting Different Marine Applications

Leisure Craft

Engine oils, steering fluids, gear lubricants, greases, coolants and maintenance products support routine servicing and seasonal protection for motorboats and leisure vessels.

Outboard Engines

Dedicated two-stroke and four-stroke lubricants provide options for conventional, direct-injection and catalyst-equipped engines.

Personal Watercraft

Specialist lubricants support selected high-output personal watercraft and other demanding marine applications.

Inboard Engines

Petrol and diesel engine oils provide solutions for leisure, commercial and specialist inboard installations.

Commercial and Heavy-Duty Vessels

Heavy-duty marine engine oils, greases, gear lubricants and ancillary products support vessels operating over extended periods and under sustained loads.

Onboard Mechanical Systems

Steering, transmission, gear, cooling and greasing products provide broader support across the vessel rather than focusing solely on the engine.

Designed for Demanding Marine Environments

Marine equipment may be exposed to humidity, saltwater, temperature changes, long operating periods and extended seasonal storage.

Rock Oil products are developed to support:

• Reliable lubrication under load.
• Protection against wear and corrosion.
• Resistance to oxidation and lubricant degradation.
• Stable performance across changing temperatures.
• Water-resistant protection for greased components.
• Cleaner mechanical and cooling systems.
• Practical servicing and preventative maintenance.

Whether maintaining a single leisure craft or managing a commercial fleet, Rock Oil can help identify suitable products across the engine, drivetrain, steering, cooling and maintenance systems.

Environmentally Considerate Marine Solutions

Rock Oil’s marine portfolio includes environmentally considerate options for selected applications.

These include:

• Biodegradable two-stroke engine oils.
• Propylene glycol-based marine coolants.
• Products designed to extend component and lubricant life.
• Corrosion-prevention products that help protect equipment during storage.
• Maintenance products developed to reduce unnecessary wear and replacement.

Biodegradable and lower-toxicity products must still be correctly matched to the engine, system and manufacturer’s requirements.

Responsible storage, application and disposal remain essential in protecting the marine environment.