When two boats share the same hull type — in this case both the Maxum 3100 SE 2009 and the Maxum 4200 SY 2008 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?

Size is the most obvious dividing line here. The Maxum 4200 SY 2008 measures 42,0 feet overall (2008), giving it roughly 9,0 additional feet of deck space compared to the Maxum 3100 SE 2009 at 33,0 feet (2009). Weight tells a clearer story for trailering families: the Maxum 4200 SY 2008 tips the scales at 27 392 lbs — 14 554 lbs less than the Maxum 3100 SE 2009 at 12 838 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 Maxum 3100 SE 2009 carries a rated maximum of 375 hp. Engine data for the Maxum 4200 SY 2008 wasn't available in our records — check the manufacturer's spec sheet before sizing a motor.Fuel capacity breaks the other way: the Maxum 3100 SE 2009 carries 165 gallons versus 48 gallons in the Maxum 4200 SY 2008. 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 Maxum 4200 SY 2008 is rated for 13 passengers, while the Maxum 3100 SE 2009 caps at 10. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Maxum 4200 SY 2008 could be the deciding factor.