The Avalon 20 ft. Catalina 2011 vs Avalon Windjammer - 18 Foot 2007 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.
On paper these two are close siblings in the size department - Avalon 20 ft. Catalina 2011 at 20,0 ft versus Avalon Windjammer - 18 Foot 2007 at 18,0 ft. Weight tells a clearer story for trailering families: the Avalon 20 ft. Catalina 2011 tips the scales at 1 750 lbs - 259 lbs more than the Avalon Windjammer - 18 Foot 2007 at 1 491 lbs. That difference is meaningful if you're working within a half-ton or three-quarter-ton truck's tow rating, especially once you factor in a motor, gear, and fuel.
Both boats share a closely matched power ceiling - 90 hp for the Avalon 20 ft. Catalina 2011 and 75 hp for the Avalon Windjammer - 18 Foot 2007. 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 Avalon Windjammer - 18 Foot 2007 carries 24 gallons versus 12 gallons in the Avalon 20 ft. Catalina 2011. 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 Avalon 20 ft. Catalina 2011 is rated for 9 passengers, while the Avalon Windjammer - 18 Foot 2007 caps at 8. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Avalon 20 ft. Catalina 2011 could be the deciding factor.
Bottom line: Choose the Avalon 20 ft. Catalina 2011 if your priority is putting more people on the water - it handles 9 passengers and at 20,0 ft it has the deck room to back that rating up comfortably. The Avalon Windjammer - 18 Foot 2007 is the smarter pick if you want a lighter, easier-to-trailer boat rated for 8 that costs less to run day-to-day.