When two boats share the same hull type — in this case both the Key West 166 SK 2011 and the Key West 1720 Pro 2009 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 166 SK 2011 at 16,0 ft versus Key West 1720 Pro 2009 at 17,0 ft. Weight tells a clearer story for trailering families: the Key West 1720 Pro 2009 tips the scales at 115 lbs — 107 lbs less than the Key West 166 SK 2011 at 8 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 120 hp, the Key West 1720 Pro 2009 has a 70-hp advantage over the Key West 166 SK 2011's 50-hp ceiling — enough to notice on acceleration and at cruising speed, particularly with a full passenger load.

For family outings this is probably the sharpest distinction between the two. The Key West 1720 Pro 2009 is rated for 5 passengers, while the Key West 166 SK 2011 caps at 4. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Key West 1720 Pro 2009 could be the deciding factor.

At this size, power-to-weight ratio matters more than outright horsepower. The Key West 166 SK 2011 comes in at 0 lbs per hp versus 1 lbs per hp for the Key West 1720 Pro 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.