When two boats share the same hull type — in this case both the Larson LX 620 SF O/B 2012 and the Larson SEi 180 LX 2009 are modified vee designs with composite 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 LX 620 SF O/B 2012 at 16,2 ft versus Larson SEi 180 LX 2009 at 17,0 ft. Weight tells a clearer story for trailering families: the Larson SEi 180 LX 2009 tips the scales at 2 365 lbs — 2 250 lbs less than the Larson LX 620 SF O/B 2012 at 115 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 Larson LX 620 SF O/B 2012 carries a rated maximum of 90 hp. Engine data for the Larson SEi 180 LX 2009 wasn't available in our records — check the manufacturer's spec sheet before sizing a motor.Fuel capacity breaks the other way: the Larson SEi 180 LX 2009 carries 23 gallons versus 19 gallons in the Larson LX 620 SF O/B 2012. On a lake day that's negligible, but for coastal cruising or long reservoir runs the extra range matters.
For family outings this is probably the sharpest distinction between the two. The Larson SEi 180 LX 2009 is rated for 8 passengers, while the Larson LX 620 SF O/B 2012 caps at 6. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Larson SEi 180 LX 2009 could be the deciding factor.
Bottom line: Choose the Larson SEi 180 LX 2009 if your priority is putting more people on the water — it handles 8 passengers and at 17,0 ft it has the deck room to back that rating up comfortably. The Larson LX 620 SF O/B 2012 is the smarter pick if you want a lighter, easier-to-trailer boat rated for 6 that costs less to run day-to-day.