When two boats share the same hull type — in this case both the Sun Tracker Party Barge 21 2011 and the Sun Tracker Party Barge® 220 DLX 2013 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 Sun Tracker Party Barge® 220 DLX 2013 measures 25,3 feet overall (2013), giving it roughly 3,4 additional feet of deck space compared to the Sun Tracker Party Barge 21 2011 at 21,9 feet (2011). Weight tells a clearer story for trailering families: the Sun Tracker Party Barge® 220 DLX 2013 tips the scales at 2 705 lbs — 2 500 lbs less than the Sun Tracker Party Barge 21 2011 at 205 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 150 hp, the Sun Tracker Party Barge® 220 DLX 2013 has a 60-hp advantage over the Sun Tracker Party Barge 21 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 Sun Tracker Party Barge 21 2011 carries 42 gallons versus 32 gallons in the Sun Tracker Party Barge® 220 DLX 2013. 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 Sun Tracker Party Barge® 220 DLX 2013 is rated for 11 passengers, while the Sun Tracker Party Barge 21 2011 caps at 9. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Sun Tracker Party Barge® 220 DLX 2013 could be the deciding factor.