The Marathon DN 16SC 2010 is a deep-V design and the Marathon Seneca 13 2011 is a modified-V 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 - Marathon DN 16SC 2010 at 16,0 ft versus Marathon Seneca 13 2011 at 13,0 ft. Weight tells a clearer story for trailering families: the Marathon DN 16SC 2010 tips the scales at 510 lbs - 360 lbs more than the Marathon Seneca 13 2011 at 150 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 50 hp, the Marathon DN 16SC 2010 has a 35-hp advantage over the Marathon Seneca 13 2011's 15-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 Marathon DN 16SC 2010 is rated for 5 passengers, while the Marathon Seneca 13 2011 caps at 4. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Marathon DN 16SC 2010 could be the deciding factor.
At this size, power-to-weight ratio matters more than outright horsepower. The Marathon Seneca 13 2011 comes in at 10 lbs per hp versus 10 lbs per hp for the Marathon DN 16SC 2010. 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 Marathon DN 16SC 2010 if your priority is putting more people on the water - it handles 5 passengers and at 16,0 ft it has the deck room to back that rating up comfortably. The Marathon Seneca 13 2011 is the smarter pick if you want a lighter, easier-to-trailer boat rated for 4 that costs less to run day-to-day.