The Catalina Yachts 30 MkI 1986 vs Catalina Yachts Catalina 390 - Fin Keel Fin Keel 2001 comparison sits squarely in the category of decisions where specs alone won't tell the whole story: intended use, storage, and long-term ownership costs all factor in.
Both boats share a closely matched power ceiling - 21 hp for the Catalina Yachts 30 MkI 1986 and 40 hp for the Catalina Yachts Catalina 390 - Fin Keel Fin Keel 2001. Real-world performance will come down more to which motor is actually bolted on, its load at the time, and whether it's a 4-stroke or 2-stroke setup. Fuel capacity breaks the other way: the Catalina Yachts Catalina 390 - Fin Keel Fin Keel 2001 carries 34 gallons versus 18 gallons in the Catalina Yachts 30 MkI 1986. On a lake day that's negligible, but for coastal cruising or long reservoir runs the extra range matters.
For family outings this is probably the sharpest distinction between the two. The Catalina Yachts Catalina 390 - Fin Keel Fin Keel 2001 is rated for 11 passengers, while the Catalina Yachts 30 MkI 1986 caps at 9. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Catalina Yachts Catalina 390 - Fin Keel Fin Keel 2001 could be the deciding factor.
The Catalina Yachts Catalina 390 - Fin Keel Fin Keel 2001 has a documented displacement of 18 874 lbs. Displacement data wasn't available for the other boat in this comparison.
Draft is a practical consideration that many buyers underestimate until they're already at the marina. The Catalina Yachts Catalina 390 - Fin Keel Fin Keel 2001 draws 7,2 ft, compared to 5,2 ft for the Catalina Yachts 30 MkI 1986. That 2,0-foot difference affects which anchorages you can access, which haul-out facilities will take you, and how carefully you need to read the tide tables in shallower cruising grounds.
For auxiliary power the Catalina Yachts Catalina 390 - Fin Keel Fin Keel 2001 carries a 40-hp engine against 21 hp on the Catalina Yachts 30 MkI 1986. Motoring range and ability to punch through a foul current or enter a tight marina under power will favour the more powerful installation.
Bottom line: The Catalina Yachts Catalina 390 - Fin Keel Fin Keel 2001 at 38,8 ft offers more living space, greater range, and a more substantial offshore capability. The Catalina Yachts 30 MkI 1986 at 30,0 ft is the easier, lower-cost option - simpler to crew and a strong choice for coastal and day sailing.