Matching a flat Marathon Jon - DN 1236 2008 against a modified vee Marathon Seneca 14T 2011 means you're likely deciding between two genuinely 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 Jon - DN 1236 2008 at 12,0 ft versus Marathon Seneca 14T 2011 at 14,3 ft. Weight tells a clearer story for trailering families: the Marathon Seneca 14T 2011 tips the scales at 218 lbs — 207 lbs less than the Marathon Jon - DN 1236 2008 at 11 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 — 7 hp for the Marathon Jon - DN 1236 2008 and 25 hp for the Marathon Seneca 14T 2011. 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 Marathon Seneca 14T 2011 is rated for 5 passengers, while the Marathon Jon - DN 1236 2008 caps at 3. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Marathon Seneca 14T 2011 could be the deciding factor.
At this size, power-to-weight ratio matters more than outright horsepower. The Marathon Jon - DN 1236 2008 comes in at 2 lbs per hp versus 9 lbs per hp for the Marathon Seneca 14T 2011. 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 Seneca 14T 2011 if your priority is putting more people on the water — it handles 5 passengers and at 14,3 ft it has the deck room to back that rating up comfortably. The Marathon Jon - DN 1236 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.