Both the Marathon DN 16SSC 2011 and the Marathon Oneida 16 2009 are modified-V designs, both built in aluminium, so the buying decision usually comes down to a handful of practical questions: how many people are you putting on the water, how far do you trailer, and what does your tow vehicle weigh?
On paper these two are close siblings in the size department - Marathon DN 16SSC 2011 at 16,0 ft versus Marathon Oneida 16 2009 at 16,0 ft. At 420 lbs and 510 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 - 40 hp for the Marathon DN 16SSC 2011 and 50 hp for the Marathon Oneida 16 2009. 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 DN 16SSC 2011 is rated for 6 passengers, while the Marathon Oneida 16 2009 caps at 5. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Marathon DN 16SSC 2011 could be the deciding factor.
At this size, power-to-weight ratio matters more than outright horsepower. The Marathon Oneida 16 2009 comes in at 10 lbs per hp versus 11 lbs per hp for the Marathon DN 16SSC 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 DN 16SSC 2011 if your priority is putting more people on the water - it handles 6 passengers and at 16,0 ft it has the deck room to back that rating up comfortably. The Marathon Oneida 16 2009 is the smarter pick if you want a lighter, easier-to-trailer boat rated for 5 that costs less to run day-to-day.