Caterpillar marine · Independent specialists · Melbourne
Caterpillar marine service, brought to your berth.
Single or twin, pleasure or commercial. Serviced to Cat’s schedule by independent specialists, with a clear rundown of what’s urgent and what can wait.
- Independent Caterpillar specialists
- Servicing Melbourne boats since 1995
- At your berth across Port Phillip Bay
- Twin Disc dealer & ZF Service Point
Your setup
Which Cat setup do you have?
Cat diesels power big flybridge cruisers and working boats alike, usually on shafts through a marine gearbox. Pick the one closest to your boat, or see what we look after behind the engine.
Cat’s E (High Performance) rating is the one Cat lists for pleasure craft, which spend little of their time at full power. On these boats, time and salt water age the engine as much as hours do, so the sea water side gets as much attention as the oil.
- Engine oil and filters
- Fuel filters, water separator and bleed
- Sea water pump impeller
- Zinc anodes
- Heat exchanger and aftercooler checks
- Exhaust riser and elbow inspection
- Belts, hoses and clamps
- Shaft seal and coupling check
Twin installations
Twin Cats, one visit.
Many Cat-powered cruisers run a pair, like the Maritimo M60 and M65 on twin C18s. We service both engines and both gearboxes in the same visit, so the pair stays on one schedule.
- Both engines and both gearboxes serviced in one visit, at your berth where possible
- Side-by-side checks, so a difference between engines shows up early
- A separate record for each engine, the history buyers and surveyors ask to see
- Haul-out work planned with your yard
What you get
You’ll know exactly where your engines stand.
Every service ends with a plain-English rundown. Each item is marked done, keep an eye on, or needs attention, so you can see what’s urgent and what can wait. Anything beyond the service is quoted first.
- A separate record for each engine and gearbox
- Kept for your survey, insurance and resale history
- What’s due next, so you can plan around the season
Under factory warranty?
If your Cat is still under its factory warranty, check the terms for what they say about servicing, parts and records, and tell us when you book so we can service it to suit. Either way, we record every visit. Your rights under the Australian Consumer Law apply in addition to these terms.
Service rundown
Twin C18 · Shaft drive · 2,100 hours
- Done
Engine oil and filters
- Done
Fuel filters and water separators
- Done
Sea water pump impellers
Replaced.
- Done
Zinc anodes
Renewed.
- Done
Gearbox oil
Clean, no sign of water.
- Keep an eye on
Aftercooler cores
Light fouling on the air side. Clean at the next service.
- Done
Belts and hoses
- Needs attention
Port exhaust riser
Rust weeping at the joint. Quoted to replace.
Something not right?
Signs your Cat wants attention.
Many problems give a warning first. If you’ve noticed one of these, it’s worth a look before it turns into a lost weekend, or a lost day’s work.
Temperature climbing at cruise
An engine that’s happy at idle but climbs under load usually points to the sea water side: a tired impeller, a blocked strainer or a fouled heat exchanger. We work through the circuit to find the restriction.
Black smoke and down on power
On hard-working marine Cats this is commonly a fouled aftercooler or turbo, worn injectors, or over-propping that stops the engine reaching rated rpm. Boost and exhaust temperatures help narrow it down.
Slowly losing top speed
If the boat has lost a few knots over a season or two, a fouled aftercooler or heat exchanger is one common cause on marine Cats, along with hull and propeller growth. On engines with a sea-water-cooled aftercooler, a corroded core can eventually let water into the engine.
A drip from the sea water pump
Water from the pump’s weep hole means a seal is on the way out. If the impeller has failed, its vanes often end up lodged in a cooler or heat exchanger downstream, so every missing piece needs finding.
Rust or salt streaks on the risers
Internal corrosion in risers and elbows can eventually let water back into the cylinders. Worth replacing before it gets there.
An alarm that comes and goes
Salt air is hard on connectors, wiring and sensors. Intermittent alarms often trace back to corrosion or a chafed loom rather than the engine itself, but each one is worth finding.
Timing
Book around the boating season.
A little planning means the boat is ready on the first good weekend, not the third.
78%
of maritime incidents reported in Victoria in 2024–25 were vessel breakdowns, most of them engine failure or running out of fuel.
Source: Safe Transport VictoriaAugust to October
Pre-season service
Book before the rush. November to Easter is our busiest period, so a service in late winter or early spring has the boat ready for the first good weekend.
Book a pre-season serviceNovember to Easter
On the water
Peak boating, and our busiest months. If an alarm won’t clear or something doesn’t feel right mid-season, call us.
Easter to July
Bigger jobs
The best time for higher-hour services, aftercooler, riser and gearbox work, and haul-outs, with the least boating missed.
Who you're dealing with
Independent Caterpillar specialists, looking after Melbourne boats since 1995.
We’re not a Cat dealer. We’re an independent marine workshop that services and repairs Caterpillar engines at your berth or in our Spotswood workshop, with genuine or quality aftermarket parts.
- Independent, not a Cat dealer
- Genuine or quality aftermarket parts
- Authorised Twin Disc dealer and ZF Marine Service Point
- Also authorised for Volvo Penta and Yanmar
Cat marine engines we service, old and new
Check the model and serial number on the engine plate when you book. Some names cover more than one engine: the C12 was sold in standard and higher-output ACERT versions, and the C12.9 is a newer 12.9-litre engine. Note the rating letter too, if you know it.
Cat diesels were fitted, as standard or as an option, to boats like the Riviera 48 and 58 Enclosed Flybridge and the Maritimo M60 and M65. Many of these hulls were also built with other engines, so check the engine plate.
Questions
What Cat owners ask us
How much does a Cat service cost?
It depends on the engine, whether you have one or two, and what’s due on its schedule. We confirm all of that and give you a clear quote before any work starts.
Are you a Caterpillar dealer?
No. We’re an independent marine workshop. We service and repair Cat engines with genuine or quality aftermarket parts, and we’re an authorised Volvo Penta, Yanmar and Twin Disc dealer, and a ZF Marine Service Point.
Do I need to bring the boat to you?
No. We service Cat engines at the berth or on the hardstand around Port Phillip Bay. Bigger jobs come into our Spotswood workshop or are done during a haul-out.
How often does a Cat need servicing?
Cat sets the maintenance intervals for each engine in its Operation and Maintenance Manual, and they vary by model and how the engine is used. We work to your engine’s own schedule and record every visit.
Which Cat do I have?
The model and serial number are on the engine plate. Send us both and we’ll know what you have. Older boats may have a 3208, 3406 or 3412, and some names cover more than one engine, like the C12 and the higher-output C12 ACERT.
I have twin Cats. Can you do both at once?
Yes. We service both engines and both gearboxes in the same visit and keep a separate record for each, so the pair stays on one schedule.
How do I book?
Use the booking form at the top of this page or call (03) 9399 5888. We aim to reply within 1 business day.
Ready when the weather is.
Tell us about your Cat and where the boat is, and we’ll take it from there.
Mariner Engineering is an independent marine service and repair provider and is not an authorised dealer of, or affiliated with, Caterpillar. Caterpillar, Cat and associated model names are trademarks of their respective owners, used here only to describe the engines we service.