Both the Nautica RIB 19 Jet IO 2011 and the Nautica RIB 20 Catamaran 2011 are rigid inflatable designs, both built in fibreglass, so 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 - Nautica RIB 19 Jet IO 2011 at 19,0 ft versus Nautica RIB 20 Catamaran 2011 at 19,5 ft. Weight tells a clearer story for trailering families: the Nautica RIB 19 Jet IO 2011 tips the scales at 3 200 lbs - 2 150 lbs more than the Nautica RIB 20 Catamaran 2011 at 1 050 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 240 hp, the Nautica RIB 19 Jet IO 2011 has a 125-hp advantage over the Nautica RIB 20 Catamaran 2011's 115-hp ceiling - enough to notice on acceleration and at cruising speed, particularly with a full passenger load. Both carry nearly identical fuel loads - 50 gal and 48 gal - so range won't be a tiebreaker here.
Both boats are rated for 16 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.
Bottom line: Performance buyers should lean toward the Nautica RIB 19 Jet IO 2011 and its 240-hp ceiling. If fuel economy and quieter running matter more than top-end speed, the Nautica RIB 20 Catamaran 2011 with its 115-hp rating is the more economical daily driver.