Matching a flat Marathon Otisco 1036 2008 against a modified vee Marathon Seneca 12 2010 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.
Size is the most obvious dividing line here. The Marathon Seneca 12 2010 measures 11,7 feet overall (2010), giving it roughly 10,7 additional feet of deck space compared to the Marathon Otisco 1036 2008 at 1,0 feet (2008). At 96 lbs and 121 lbs respectively, both sit in a similar weight class — either should pair comfortably with most mid-size SUVs and half-ton trucks, though always confirm your specific tow rating with the motor added.
Both boats share a closely matched power ceiling — 3 hp for the Marathon Otisco 1036 2008 and 10 hp for the Marathon Seneca 12 2010. 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 12 2010 is rated for 3 passengers, while the Marathon Otisco 1036 2008 caps at 2. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Marathon Seneca 12 2010 could be the deciding factor.
At this size, power-to-weight ratio matters more than outright horsepower. The Marathon Seneca 12 2010 comes in at 12 lbs per hp versus 32 lbs per hp for the Marathon Otisco 1036 2008. 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 12 2010 if your priority is putting more people on the water — it handles 3 passengers and at 11,7 ft it has the deck room to back that rating up comfortably. The Marathon Otisco 1036 2008 is the smarter pick if you want a lighter, easier-to-trailer boat rated for 2 that costs less to run day-to-day.