When two boats share the same hull type — in this case both the SeaArk RiverCat 180 CC 2012 and the SeaArk Stealth 172 2009 are modified 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?
On paper these two are close siblings in the size department — SeaArk RiverCat 180 CC 2012 at 18,0 ft versus SeaArk Stealth 172 2009 at 17,0 ft. Weight tells a clearer story for trailering families: the SeaArk RiverCat 180 CC 2012 tips the scales at 1 193 lbs — 268 lbs more than the SeaArk Stealth 172 2009 at 925 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 140 hp, the SeaArk RiverCat 180 CC 2012 has a 40-hp advantage over the SeaArk Stealth 172 2009's 100-hp ceiling — enough to notice on acceleration and at cruising speed, particularly with a full passenger load. Fuel capacity breaks the other way: the SeaArk Stealth 172 2009 carries 18 gallons versus 3 gallons in the SeaArk RiverCat 180 CC 2012. 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 SeaArk RiverCat 180 CC 2012 is rated for 5 passengers, while the SeaArk Stealth 172 2009 caps at 4. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the SeaArk RiverCat 180 CC 2012 could be the deciding factor.
At this size, power-to-weight ratio matters more than outright horsepower. The SeaArk RiverCat 180 CC 2012 comes in at 9 lbs per hp versus 9 lbs per hp for the SeaArk Stealth 172 2009. The lower the ratio the more explosive the acceleration — meaningful on a short RIB where bursts of speed, quick planing, and agility in surf or tight waterways define the experience.
Bottom line: Choose the SeaArk RiverCat 180 CC 2012 if your priority is putting more people on the water — it handles 5 passengers and at 18,0 ft it has the deck room to back that rating up comfortably. The SeaArk Stealth 172 2009 is the smarter pick if you want a lighter, easier-to-trailer boat rated for 4 that costs less to run day-to-day.