Matching a deep vee Zodiac Medline 580 2013 against a inflatable rigid Zodiac Pro Open 850 2011 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 Pro Open 850 2011 measures 27,9 feet overall (2011), giving it roughly 8,9 additional feet of deck space compared to the Zodiac Medline 580 2013 at 19,0 feet (2013). Weight tells a clearer story for trailering families: the Zodiac Pro Open 850 2011 tips the scales at 3 307 lbs — 1 982 lbs less than the Zodiac Medline 580 2013 at 1 325 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 350 hp, the Zodiac Pro Open 850 2011 has a 270-hp advantage over the Zodiac Medline 580 2013's 80-hp ceiling — enough to notice on acceleration and at cruising speed, particularly with a full passenger load. Fuel capacity breaks the other way: the Zodiac Pro Open 850 2011 carries 106 gallons versus 23 gallons in the Zodiac Medline 580 2013. On a lake day that's negligible, but for coastal cruising or long reservoir runs the extra range matters.
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 Pro Open 850 2011 caps at 8. 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 Pro Open 850 2011 comes in at 9 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 Pro Open 850 2011 has a documented top speed of 57 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 Pro Open 850 2011 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 Pro Open 850 2011 is the smarter pick if you want a lighter, easier-to-trailer boat rated for 8 that costs less to run day-to-day.