Matching a flat Marathon Otisco 1236 2008 against a modified vee Marathon Seneca 14RDS 2012 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 Otisco 1236 2008 at 12,0 ft versus Marathon Seneca 14RDS 2012 at 14,3 ft. Weight tells a clearer story for trailering families: the Marathon Seneca 14RDS 2012 tips the scales at 233 lbs — 222 lbs less than the Marathon Otisco 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.
The Marathon Seneca 14RDS 2012 tops out at 25 hp. Engine specs for the Marathon Otisco 1236 2008 aren't listed — confirm with a dealer before selecting an outboard.
For family outings this is probably the sharpest distinction between the two. The Marathon Seneca 14RDS 2012 is rated for 5 passengers, while the Marathon Otisco 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 14RDS 2012 could be the deciding factor.
Bottom line: Choose the Marathon Seneca 14RDS 2012 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 Otisco 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.