When two boats share the same hull type — in this case both the Key West 1720 DC 2009 and the Key West 198 SK 2013 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 — Key West 1720 DC 2009 at 17,0 ft versus Key West 198 SK 2013 at 19,0 ft. Weight tells a clearer story for trailering families: the Key West 198 SK 2013 tips the scales at 135 lbs — 123 lbs less than the Key West 1720 DC 2009 at 12 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 share a closely matched power ceiling — 120 hp for the Key West 1720 DC 2009 and 140 hp for the Key West 198 SK 2013. Real-world performance will come down more to which motor is actually bolted on, its load at the time, and whether it's a 4-stroke or 2-stroke setup. Fuel capacity breaks the other way: the Key West 1720 DC 2009 carries 31 gallons versus 3 gallons in the Key West 198 SK 2013. On a lake day that's negligible, but for coastal cruising or long reservoir runs the extra range matters.
The Key West 1720 DC 2009 is rated for up to 5 people. Passenger data for the Key West 198 SK 2013 wasn't available.
Bottom line: Performance buyers should lean toward the Key West 198 SK 2013 and its 140-hp ceiling. If fuel economy and quieter running matter more than top-end speed, the Key West 1720 DC 2009 with its 120-hp rating is the more economical daily driver.