The Sun Tracker Party Barge 18 2004 vs Sun Tracker Party Barge 21 Signature Series 2009 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 — Sun Tracker Party Barge 18 2004 at 18,0 ft versus Sun Tracker Party Barge 21 Signature Series 2009 at 21,0 ft. At 138 lbs and 214 lbs respectively, both sit in a similar weight class — either should pair comfortably with most mid-size SUVs and half-ton trucks, though always confirm your specific tow rating with the motor added.
The Sun Tracker Party Barge 21 Signature Series 2009 tops out at 90 hp. Engine specs for the Sun Tracker Party Barge 18 2004 aren't listed — confirm with a dealer before selecting an outboard.Fuel capacity breaks the other way: the Sun Tracker Party Barge 18 2004 carries 26 gallons versus 3 gallons in the Sun Tracker Party Barge 21 Signature Series 2009. 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 21 Signature Series 2009 is rated for 13 passengers, while the Sun Tracker Party Barge 18 2004 caps at 7. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Sun Tracker Party Barge 21 Signature Series 2009 could be the deciding factor.
Bottom line: Choose the Sun Tracker Party Barge 21 Signature Series 2009 if your priority is putting more people on the water — it handles 13 passengers and at 21,0 ft it has the deck room to back that rating up comfortably. The Sun Tracker Party Barge 18 2004 is the smarter pick if you want a lighter, easier-to-trailer boat rated for 7 that costs less to run day-to-day.