When two boats share the same hull type — in this case both the Duckworth 18 2011 and the Duckworth Navigator Sport 175 2008 are deep 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 — Duckworth 18 2011 at 18,0 ft versus Duckworth Navigator Sport 175 2008 at 17,0 ft. Weight tells a clearer story for trailering families: the Duckworth 18 2011 tips the scales at 2 375 lbs — 2 361 lbs more than the Duckworth Navigator Sport 175 2008 at 14 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 — 115 hp for the Duckworth 18 2011 and 115 hp for the Duckworth Navigator Sport 175 2008. 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. Both carry nearly identical fuel loads — 42 gal and 42 gal — so range won't be a tiebreaker here.

Both boats are rated for 5 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.

At this size, power-to-weight ratio matters more than outright horsepower. The Duckworth Navigator Sport 175 2008 comes in at 0 lbs per hp versus 21 lbs per hp for the Duckworth 18 2011. 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.