The Voyager Marine 18 ft. Sport Fish 2013 is a pontoon design and the Voyager Marine Series 7000 - 1670 2008 is a flat-bottom design, so you're likely deciding between two noticeably different on-water experiences. Hull type shapes everything from ride quality and fuel burn to dock handling and resale trajectory.
On paper these two are close siblings in the size department - Voyager Marine 18 ft. Sport Fish 2013 at 18,0 ft versus Voyager Marine Series 7000 - 1670 2008 at 16,0 ft. Weight tells a clearer story for trailering families: the Voyager Marine 18 ft. Sport Fish 2013 tips the scales at 1 450 lbs - 1 175 lbs more than the Voyager Marine Series 7000 - 1670 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.
The power gap is worth calling out. Rated to 75 hp, the Voyager Marine 18 ft. Sport Fish 2013 has a 40-hp advantage over the Voyager Marine Series 7000 - 1670 2008's 35-hp ceiling - enough to notice on acceleration and at cruising speed, particularly with a full passenger load.
For family outings this is probably the sharpest distinction between the two. The Voyager Marine 18 ft. Sport Fish 2013 is rated for 8 passengers, while the Voyager Marine Series 7000 - 1670 2008 caps at 3. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Voyager Marine 18 ft. Sport Fish 2013 could be the deciding factor.
At this size, power-to-weight ratio matters more than outright horsepower. The Voyager Marine Series 7000 - 1670 2008 comes in at 8 lbs per hp versus 19 lbs per hp for the Voyager Marine 18 ft. Sport Fish 2013. 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.
Bottom line: Choose the Voyager Marine 18 ft. Sport Fish 2013 if your priority is putting more people on the water - it handles 8 passengers and at 18,0 ft it has the deck room to back that rating up comfortably. The Voyager Marine Series 7000 - 1670 2008 is the smarter pick if you want a lighter, easier-to-trailer boat rated for 3 that costs less to run day-to-day.