When two boats share the same hull type — in this case both the Monterey 318SSX 2009 and the Monterey 340SY 2013 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 340SY 2013 measures 35,3 feet overall (2013), giving it roughly 4,3 additional feet of deck space compared to the Monterey 318SSX 2009 at 31,0 feet (2009). Weight tells a clearer story for trailering families: the Monterey 340SY 2013 tips the scales at 147 lbs — 139 lbs less than the Monterey 318SSX 2009 at 8 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 400 hp, the Monterey 340SY 2013 has a 80-hp advantage over the Monterey 318SSX 2009'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 318SSX 2009 carries 142 gallons versus 21 gallons in the Monterey 340SY 2013. On a lake day that's negligible, but for coastal cruising or long reservoir runs the extra range matters.