When two boats share the same hull type — in this case both the Weldcraft Marine 18 SJ 2010 and the Weldcraft Marine 20 2011 are deep vee 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 Weldcraft Marine 18 SJ 2010 measures 18,1 feet overall (2010), giving it roughly 16,1 additional feet of deck space compared to the Weldcraft Marine 20 2011 at 2,0 feet (2011). Weight tells a clearer story for trailering families: the Weldcraft Marine 18 SJ 2010 tips the scales at 205 lbs — 180 lbs more than the Weldcraft Marine 20 2011 at 25 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 are rated for 6 passengers — a good fit for a family of four or five plus guests. Comfort at capacity is another matter; the longer hull typically means more seat options and better weight distribution.
Bottom line: The Weldcraft Marine 18 SJ 2010 at 18,1 ft is the right call if deck space, comfort, and entertaining are top of your list. The Weldcraft Marine 20 2011 at 2,0 ft wins on trailering ease, likely lower purchase price, and simpler docking — a solid choice for a buyer who wants more boat for less money.