When two boats share the same hull type — in this case both the Avalon 18 ft. Windjammer 2011 and the Avalon Paradise 20 ft. 2010 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?
Size is the most obvious dividing line here. The Avalon 18 ft. Windjammer 2011 measures 18,0 feet overall (2011), giving it roughly 16,0 additional feet of deck space compared to the Avalon Paradise 20 ft. 2010 at 2,0 feet (2010). Weight tells a clearer story for trailering families: the Avalon 18 ft. Windjammer 2011 tips the scales at 165 lbs — 147 lbs more than the Avalon Paradise 20 ft. 2010 at 18 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.
The power gap is worth calling out. Rated to 115 hp, the Avalon Paradise 20 ft. 2010 has a 25-hp advantage over the Avalon 18 ft. Windjammer 2011's 90-hp ceiling — enough to notice on acceleration and at cruising speed, particularly with a full passenger load. Fuel capacity breaks the other way: the Avalon Paradise 20 ft. 2010 carries 36 gallons versus 24 gallons in the Avalon 18 ft. Windjammer 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 Paradise 20 ft. 2010 is rated for 10 passengers, while the Avalon 18 ft. Windjammer 2011 caps at 9. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Avalon Paradise 20 ft. 2010 could be the deciding factor.
At this size, power-to-weight ratio matters more than outright horsepower. The Avalon Paradise 20 ft. 2010 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.
One place where both boats are genuinely identical is tube construction: both run 2 aluminum tubes at 25" diameter. That shared spec means stability and buoyancy characteristics are closely matched — the ride difference you'll feel between them comes primarily from deck length, weight distribution, and motor choice.
Bottom line: Choose the Avalon Paradise 20 ft. 2010 if your priority is putting more people on the water — it handles 10 passengers and at 2,0 ft it has the deck room to back that rating up comfortably. The Avalon 18 ft. Windjammer 2011 is the smarter pick if you want a lighter, easier-to-trailer boat rated for 9 that costs less to run day-to-day.