The Mariah FS18 2009 vs Mariah SX20 Bow Rider 2007 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 - Mariah FS18 2009 at 18,0 ft versus Mariah SX20 Bow Rider 2007 at 20,0 ft. At 3 100 lbs and 3 200 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 260 hp, the Mariah SX20 Bow Rider 2007 has a 70-hp advantage over the Mariah FS18 2009's 190-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 SX20 Bow Rider 2007 carries 38 gallons versus 22 gallons in the Mariah FS18 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 Mariah SX20 Bow Rider 2007 is rated for 10 passengers, while the Mariah FS18 2009 caps at 8. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Mariah SX20 Bow Rider 2007 could be the deciding factor.
Bottom line: Choose the Mariah SX20 Bow Rider 2007 if your priority is putting more people on the water - it handles 10 passengers and at 20,0 ft it has the deck room to back that rating up comfortably. The Mariah FS18 2009 is the smarter pick if you want a lighter, easier-to-trailer boat rated for 8 that costs less to run day-to-day.