Both the Larson SEi 180 Ski Fish I/O 2007 and the Larson SEi 180 Ski Fish O/B 2007 are modified-V 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 - Larson SEi 180 Ski Fish I/O 2007 at 17,0 ft versus Larson SEi 180 Ski Fish O/B 2007 at 17,0 ft. Weight tells a clearer story for trailering families: the Larson SEi 180 Ski Fish I/O 2007 tips the scales at 2 650 lbs - 950 lbs more than the Larson SEi 180 Ski Fish O/B 2007 at 1 700 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 225 hp, the Larson SEi 180 Ski Fish I/O 2007 has a 75-hp advantage over the Larson SEi 180 Ski Fish O/B 2007's 150-hp ceiling - enough to notice on acceleration and at cruising speed, particularly with a full passenger load. Both carry nearly identical fuel loads - 23 gal and 23 gal - so range won't be a tiebreaker here.

Both boats are rated for 6 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 Larson SEi 180 Ski Fish O/B 2007 comes in at 11 lbs per hp versus 12 lbs per hp for the Larson SEi 180 Ski Fish I/O 2007. 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.