When two boats share the same hull type — in this case both the Avalon 18 ft. Windjammer 2011 and the Avalon Catalina 18 ft. 2009 are pontoon designs with aluminum construction — the buying decision usually comes down to a handful of practical questions: how many people are you putting on the water, how far do you trailer, and what does your tow vehicle weigh?
On paper these two are close siblings in the size department — Avalon 18 ft. Windjammer 2011 at 18,0 ft versus Avalon Catalina 18 ft. 2009 at 18,0 ft. Weight tells a clearer story for trailering families: the Avalon 18 ft. Windjammer 2011 tips the scales at 165 lbs — 149 lbs more than the Avalon Catalina 18 ft. 2009 at 16 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 18 ft. Windjammer 2011 and 75 hp for the Avalon Catalina 18 ft. 2009. 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.
For family outings this is probably the sharpest distinction between the two. The Avalon 18 ft. Windjammer 2011 is rated for 9 passengers, while the Avalon Catalina 18 ft. 2009 caps at 8. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Avalon 18 ft. Windjammer 2011 could be the deciding factor.
At this size, power-to-weight ratio matters more than outright horsepower. The Avalon Catalina 18 ft. 2009 comes in at 0 lbs per hp versus 2 lbs per hp for the Avalon 18 ft. Windjammer 2011. The lower the ratio the more explosive the acceleration — meaningful on a short RIB where bursts of speed, quick planing, and agility in surf or tight waterways define the experience.
Both are 2-tube and 2-tube pontoon designs respectively. Tube diameter and gauge affect stability and load capacity — more so than most buyers realize when comparing on paper.
Bottom line: Choose the Avalon 18 ft. Windjammer 2011 if your priority is putting more people on the water — it handles 9 passengers and at 18,0 ft it has the deck room to back that rating up comfortably. The Avalon Catalina 18 ft. 2009 is the smarter pick if you want a lighter, easier-to-trailer boat rated for 8 that costs less to run day-to-day.