When two boats share the same hull type — in this case both the Achilles HB-315LX 2008 and the Achilles HB-350LX 2013 are inflatable rigid designs with fiberglass construction — 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?
Size is the most obvious dividing line here. The Achilles HB-350LX 2013 measures 11,5 feet overall (2013), giving it roughly 10,5 additional feet of deck space compared to the Achilles HB-315LX 2008 at 1,0 feet (2008). At 128 lbs and 161 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 — 15 hp for the Achilles HB-315LX 2008 and 20 hp for the Achilles HB-350LX 2013. 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 HB-350LX 2013 is rated for 6 passengers, while the Achilles HB-315LX 2008 caps at 5. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Achilles HB-350LX 2013 could be the deciding factor.
At this size, power-to-weight ratio matters more than outright horsepower. The Achilles HB-350LX 2013 comes in at 8 lbs per hp versus 9 lbs per hp for the Achilles HB-315LX 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.
The Achilles HB-350LX 2013 is an inflatable design — lighter, easier to store, and quicker to launch from a beach or dock without a slipway. The Achilles HB-315LX 2008 is a rigid hull, which typically offers a more confident ride in chop and easier maintenance over the long term.
Bottom line: Choose the Achilles HB-350LX 2013 if your priority is putting more people on the water — it handles 6 passengers and at 11,5 ft it has the deck room to back that rating up comfortably. The Achilles HB-315LX 2008 is the smarter pick if you want a lighter, easier-to-trailer boat rated for 5 that costs less to run day-to-day.