Matching a inflatable rigid Achilles SG-156 2008 against a inflatable non rigid Achilles SU-16 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.
On paper these two are close siblings in the size department — Achilles SG-156 2008 at 15,0 ft versus Achilles SU-16 2010 at 16,0 ft. Weight tells a clearer story for trailering families: the Achilles SU-16 2010 tips the scales at 378 lbs — 106 lbs less than the Achilles SG-156 2008 at 272 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 — 55 hp for the Achilles SG-156 2008 and 75 hp for the Achilles SU-16 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 Achilles SU-16 2010 is rated for 9 passengers, while the Achilles SG-156 2008 caps at 8. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Achilles SU-16 2010 could be the deciding factor.
At this size, power-to-weight ratio matters more than outright horsepower. The Achilles SG-156 2008 comes in at 5 lbs per hp versus 5 lbs per hp for the Achilles SU-16 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 Achilles SU-16 2010 if your priority is putting more people on the water — it handles 9 passengers and at 16,0 ft it has the deck room to back that rating up comfortably. The Achilles SG-156 2008 is the smarter pick if you want a lighter, easier-to-trailer boat rated for 8 that costs less to run day-to-day.