Monohull · 6 documented fitments
Propeller upgrade for the Catalina 30 — what fits, what changes.
Drawn from 6 documented Catalina 30 fitments: the common setup is an Autoprop H20 behind the Universal M25. Typical result: 300–400 fewer RPM at cruise and up to 20% fuel saved over fixed pitch.
The fitment card
Documented engine variants & what they wear
Aggregated from 6 real installations — not a size chart, a service record.
| Engine | Power / max RPM | Drive | Typical ratio | Documented propeller | Rotation | Records |
|---|---|---|---|---|---|---|
| Universal M25 | 21 hp / 3200 | Shaft | 2:1 | Autoprop H20 | Right-hand | 2 |
| Universal M25XP | 23 hp / 3200 | Shaft | 2:1 | Varifold 2-blade | Right-hand | 2 |
| Universal M35 | 30 hp / 3200 | Shaft | 1.79:1 | Autoprop H5 | Right-hand | 1 |
| Atomic 4 | 18 hp / 2500 | Shaft | 1:1 | Autoprop H20 | Right-hand | 1 |
Indicative only — gearboxes and apertures vary between years and repowers, which is why every supplied propeller is verified against your boat first. Data current as of 2026.
Your numbers
What the change feels like on a Catalina 30
Indicative curves for this size of boat — drag the cruise line. The independent-test pattern: the same six knots on several hundred fewer RPM, with the fuel flow following.
Worth knowing
Considerations for the Catalina 30
- 4 engine variants are documented for this model — repowers included. Sizing follows your engine and ratio, not the year in the brochure.
- Tip clearance rules the maximum diameter — roughly 10–15% of prop diameter to the hull. The Builder asks; we verify before supply.
Catalina 30 propeller questions
What size propeller does a Catalina 30 take?
Documented Catalina 30 installations most commonly run an Autoprop H20, matched to the Universal M25 on a shaft drive. Exact size depends on your engine, gearbox ratio and aperture — every recommendation is verified by an engineer before supply.
How much fuel would a Catalina 30 save with an Autoprop?
Typical savings over a fixed-pitch propeller are up to 20% at cruise (documented band 15–30%, honestly less if you already run a folding or feathering prop). Put your engine hours and diesel price into the fuel calculator for your own numbers — then the Builder for a verified recommendation.
My Catalina 30 has a different engine than shown — does the data still help?
Yes. Repowers are common and the database usually holds several engine variants per model. The Builder starts from your actual engine and gearbox; the model records confirm diameters and clearances that are known to work on this hull.
Get the verified recommendation for your Catalina 30
The Builder pre-fills from these 6 documented fitments — confirm your engine and gearbox, and an engineer replies within one business day.