When two boats share the same hull type — in this case both the Achilles RS-126 2008 and the Achilles SPD-310 2010 are inflatable non rigid designs with inflatable 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?
On paper these two are close siblings in the size department — Achilles RS-126 2008 at 12,0 ft versus Achilles SPD-310 2010 at 10,2 ft. At 1 lbs and 101 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.
The Achilles SPD-310 2010 tops out at 10 hp. Engine specs for the Achilles RS-126 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 Achilles RS-126 2008 is rated for 7 passengers, while the Achilles SPD-310 2010 caps at 4. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Achilles RS-126 2008 could be the deciding factor.
Bottom line: Choose the Achilles RS-126 2008 if your priority is putting more people on the water — it handles 7 passengers and at 12,0 ft it has the deck room to back that rating up comfortably. The Achilles SPD-310 2010 is the smarter pick if you want a lighter, easier-to-trailer boat rated for 4 that costs less to run day-to-day.