When two boats share the same hull type — in this case both the Mariah G21 2010 and the Mariah R21 2012 are modified vee designs with fiberglass 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 — Mariah G21 2010 at 20,8 ft versus Mariah R21 2012 at 21,4 ft. At 39 lbs and 34 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 power gap is worth calling out. Rated to 300 hp, the Mariah R21 2012 has a 30-hp advantage over the Mariah G21 2010's 270-hp ceiling — enough to notice on acceleration and at cruising speed, particularly with a full passenger load. Fuel capacity breaks the other way: the Mariah G21 2010 carries 44 gallons versus 35 gallons in the Mariah R21 2012. On a lake day that's negligible, but for coastal cruising or long reservoir runs the extra range matters.
Both boats are rated for 1 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: Performance buyers should lean toward the Mariah R21 2012 and its 300-hp ceiling. If fuel economy and quieter running matter more than top-end speed, the Mariah G21 2010 with its 270-hp rating is the more economical daily driver.