Both the Crestliner CR 1648 MTS 2008 and the Crestliner Sportsman 18 SC 2007 are modified-V designs, so 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 - Crestliner CR 1648 MTS 2008 at 15,0 ft versus Crestliner Sportsman 18 SC 2007 at 18,0 ft. Weight tells a clearer story for trailering families: the Crestliner Sportsman 18 SC 2007 tips the scales at 610 lbs - 335 lbs less than the Crestliner CR 1648 MTS 2008 at 275 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.

Both boats share a closely matched power ceiling - 35 hp for the Crestliner CR 1648 MTS 2008 and 50 hp for the Crestliner Sportsman 18 SC 2007. Real-world performance will come down more to which motor is actually bolted on, its load at the time, and whether it's a 4-stroke or 2-stroke setup.

For family outings this is probably the sharpest distinction between the two. The Crestliner Sportsman 18 SC 2007 is rated for 7 passengers, while the Crestliner CR 1648 MTS 2008 caps at 4. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Crestliner Sportsman 18 SC 2007 could be the deciding factor.

At this size, power-to-weight ratio matters more than outright horsepower. The Crestliner CR 1648 MTS 2008 comes in at 8 lbs per hp versus 12 lbs per hp for the Crestliner Sportsman 18 SC 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.