Matching a inflatable non rigid Zodiac Cadet 310 S 2008 against a deep vee Zodiac Medline 580 2013 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 Zodiac Medline 580 2013 measures 19,0 feet overall (2013), giving it roughly 18,0 additional feet of deck space compared to the Zodiac Cadet 310 S 2008 at 1,0 feet (2008). Weight tells a clearer story for trailering families: the Zodiac Medline 580 2013 tips the scales at 1 325 lbs — 1 232 lbs less than the Zodiac Cadet 310 S 2008 at 93 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.
The power gap is worth calling out. Rated to 80 hp, the Zodiac Medline 580 2013 has a 65-hp advantage over the Zodiac Cadet 310 S 2008's 15-hp ceiling — enough to notice on acceleration and at cruising speed, particularly with a full passenger load.
For family outings this is probably the sharpest distinction between the two. The Zodiac Medline 580 2013 is rated for 12 passengers, while the Zodiac Cadet 310 S 2008 caps at 5. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Zodiac Medline 580 2013 could be the deciding factor.
At this size, power-to-weight ratio matters more than outright horsepower. The Zodiac Cadet 310 S 2008 comes in at 6 lbs per hp versus 17 lbs per hp for the Zodiac Medline 580 2013. 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 Zodiac Cadet 310 S 2008 has a documented top speed of 22 mph. Speed data wasn't available for the other model.
The Zodiac Medline 580 2013 is an inflatable design — lighter, easier to store, and quicker to launch from a beach or dock without a slipway. The Zodiac Cadet 310 S 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 Zodiac Medline 580 2013 if your priority is putting more people on the water — it handles 12 passengers and at 19,0 ft it has the deck room to back that rating up comfortably. The Zodiac Cadet 310 S 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.