The Catalina 320 on Port Phillip
- Built
- 1993 – 2008
- Length
- 32.5 ft
- Drive
- Shaft drive
- Original engine
- Yanmar 3GM30F (1997–c.2005) · Westerbeke 29B (1995–96) · Perkins M30 (1993–94)
The Catalina 320 is one of the most successful 32-footers ever built, and Melbourne has a proper fleet — St Kilda and the bay’s eastern marinas in particular — with boats holding value near $100,000 when well kept.
Here’s the tell: when we surveyed every 320 listed for sale in Victoria, every single one was still on its original discontinued engine. This fleet is due, and the owners know their boats are worth the investment.
3GM30F, Westerbeke 29B, Perkins M30 — all out of production
The 320’s engine history is a tour of discontinued diesels: Perkins M30 for the first hulls, the Westerbeke 29B mid-decade — a brand with no Victorian dealer at all, every part freighted from Queensland or the US — then the Yanmar 3GM30F for the long production run. The GM series was superseded more than twenty years ago.
Catalina themselves validated the modern answer: late Mk II hulls shipped from the factory with the Yanmar 3YM30 — the direct successor line to the 3GM30F. A 3YM30AE conversion is as close to a factory-blessed repower as it gets.
Why these engines reach the end
- Raw-water-cooled 3GM30F blocks now 20–30 years into a design life they were never meant to reach
- Westerbeke 29B parts a freight-and-wait exercise — no local dealer support
- Exhaust elbow and mixing-elbow corrosion — the classic GM-series failure
- Perkins M30 spares scarce; marinisation parts scarcer
The pattern across every brand: sailing auxiliaries corrode out long before they wear out. At 50–100 engine hours a year, the calendar — not the hour meter — decides when a yacht diesel is done. Repower or rebuild? Read our honest guide.
What we fit in the Catalina 320
Yanmar 3YM30AE
Our recommendation29 hp · 3-cylinder · shaft drive · mechanical simplicity
- The direct successor to the 3GM30F — Catalina fitted the 3YM30 from the factory in late Mk II boats
- Compact, freshwater-cooled and mechanically governed — no electronics to fail offshore
- 2-year leisure warranty, extendable under Yanmar’s program — ask us about 5-year coverage
Volvo Penta D1-30
The alternative29 hp · 3-cylinder · shaft drive
The same 29 hp class with Volvo’s 3-year helm-to-prop warranty — a strong choice if you prefer Volvo support. Real-world 320 conversions exist for both paths; we’ll advise on fit at inspection.
Volvo Penta D1-30 specificationsWhat a Catalina 320 repower costs
Typical for a Catalina 320 shaft repower including engine, mounts, exhaust and sea trial. Fixed quote after inspection.
How your repower runs
- 1
Inspection & fixed quote
We survey your engine, beds, shaft or saildrive, exhaust and electrics — at your berth or on the hard — and quote the complete job fixed, usually within days.
- 2
Book the yard
You book the hardstand and we coordinate dates. Royals (Royal Victorian Yacht Club) and Savages Wharf at Williamstown are ideal for us; we also work at Wyndham Harbour and Sandringham YC with some added travel cost.
- 3
Out with the old
Old engine out, bay cleaned and prepared — and we dispose of your old engine as part of the job at no extra cost.
- 4
In with the new
New beds and mounts, engine in, shaft or saildrive fitted and aligned, exhaust, cooling, fuel, electrics, controls and panel — engineered, not improvised.
- 5
Sea trial & handover
Commissioning checks, a proper sea trial on the bay, factory warranty registration and your service schedule. You get a finished boat, not a box of loose ends.
Factory warranty, dealer-registered
Volvo Penta — 3 years
Full “helm to prop” leisure coverage — engine, transmission or saildrive, controls and genuine accessories — with no engine-hour cap.
Yanmar — 2 years, extendable
24-month leisure warranty as standard, with Yanmar’s extended program taking eligible engines to 5 years of coverage — ask us when we quote.
As an authorised dealer for both brands we supply, install, commission and register every engine — one job, one responsible party, warranty watertight.
Catalina 320 repower — your questions answered
My 3GM30F only has 3,000 hours — surely it’s got life left?
Hours flatter old sailboat engines. At 50–100 hours a year, a 3GM30F’s enemy has been salt water and time, not work: these are raw-water-cooled blocks corroding from the inside for over two decades. “Low hours” on a 25-year-old GM is not the reassurance it sounds like.
I have the Westerbeke 29B — can you still get parts instead?
Sometimes, with patience — there’s no Victorian Westerbeke dealer, so everything comes by freight. We’ll always give you the honest comparison: on a 29B with a known issue, the repair-vs-repower maths usually isn’t close.
Will the 3YM30AE bolt straight in?
It’s a well-trodden conversion rather than a literal bolt-in — we engineer mounts, shaft alignment, exhaust and cooling to suit, which is included in every installation and covered by the fixed quote.
Where does the work happen?
At Williamstown, minutes from our Spotswood workshop — Royals (Royal Victorian Yacht Club) and Savages Wharf are our preferred yards. We can also repower at Wyndham Harbour or Sandringham Yacht Club, with some additional travel cost. You book the hardstand (we’ll point you to the right people) and we handle everything from there. Geelong owners: we’ll ask you to bring the boat up to Williamstown.
How long does a repower take?
A standard repower is about two weeks on the hardstand. Engine lead times are currently reasonable — but plan ahead a few weeks so the engine is on the floor before your boat comes out of the water.
What warranty comes with the new engine?
Volvo Penta engines carry a 3-year factory “helm to prop” leisure warranty with no engine-hour cap. Yanmar engines carry a 24-month leisure warranty, and Yanmar’s extended program can take eligible engines to 5 years of coverage — ask us when we quote. As an authorised dealer for both brands, we commission and register every engine so your warranty is watertight.
Can you fit an engine I buy elsewhere?
No — we install engines we supply. That’s not a sales line: it’s how we can stand behind the entire job, from engine to beds to sea trial, under one warranty and one responsible party.
What happens to my old engine?
We remove and dispose of it as part of the job, at no extra cost.
What about an electric conversion?
We’re developing an electric repower offering in-house and will be bringing it to market. If you’re weighing diesel against electric, talk to us before committing either way — we’ll give you the honest state of play for your boat and how you use it.
Request a Catalina 320 repower quote
Tell us your boat, where it's berthed, what engine it has now (roughly is fine) and how you use it — we'll come back with honest advice and a fixed quote, usually within a few days.
Boat model names are used to describe the vessels we service; Mariner Engineering is not affiliated with the boats' designers or builders. Mariner Engineering is an authorised Volvo Penta and Yanmar dealer.