When two boats share the same hull type — in this case both the Monterey 320SY 2012 and the Monterey 400SY 2012 are deep 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 Monterey 400SY 2012 measures 41,0 feet overall (2012), giving it roughly 7,2 additional feet of deck space compared to the Monterey 320SY 2012 at 33,8 feet (2012). Weight tells a clearer story for trailering families: the Monterey 320SY 2012 tips the scales at 132 lbs — 110 lbs more than the Monterey 400SY 2012 at 22 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 435 hp, the Monterey 400SY 2012 has a 115-hp advantage over the Monterey 320SY 2012's 320-hp ceiling — enough to notice on acceleration and at cruising speed, particularly with a full passenger load. Fuel capacity breaks the other way: the Monterey 400SY 2012 carries 33 gallons versus 18 gallons in the Monterey 320SY 2012. On a lake day that's negligible, but for coastal cruising or long reservoir runs the extra range matters.