When two boats share the same hull type — in this case both the Larson 180 Sport I/O 2007 and the Larson SEi 180 Ski Fish I/O 2007 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 — Larson 180 Sport I/O 2007 at 17,0 ft versus Larson SEi 180 Ski Fish I/O 2007 at 17,0 ft. Weight tells a clearer story for trailering families: the Larson 180 Sport I/O 2007 tips the scales at 2 375 lbs — 2 110 lbs more than the Larson SEi 180 Ski Fish I/O 2007 at 265 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 35-hp advantage over the Larson 180 Sport I/O 2007's 190-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.

For family outings this is probably the sharpest distinction between the two. The Larson 180 Sport I/O 2007 is rated for 8 passengers, while the Larson SEi 180 Ski Fish I/O 2007 caps at 6. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Larson 180 Sport I/O 2007 could be the deciding factor.

At this size, power-to-weight ratio matters more than outright horsepower. The Larson SEi 180 Ski Fish I/O 2007 comes in at 1 lbs per hp versus 13 lbs per hp for the Larson 180 Sport 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.