When two boats share the same hull type — in this case both the Zodiac Medline II 2012 and the Zodiac Pro Open 650 2013 are deep vee 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?

On paper these two are close siblings in the size department — Zodiac Medline II 2012 at 19,7 ft versus Zodiac Pro Open 650 2013 at 21,3 ft. At 1 521 lbs and 1 477 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 — 150 hp for the Zodiac Medline II 2012 and 150 hp for the Zodiac Pro Open 650 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. Fuel capacity breaks the other way: the Zodiac Medline II 2012 carries 58 gallons versus 32 gallons in the Zodiac Pro Open 650 2013. On a lake day that's negligible, but for coastal cruising or long reservoir runs the extra range matters.

Both boats are rated for 5 passengers — a good fit for a family of four or five plus guests. Comfort at capacity is another matter; the longer hull typically means more seat options and better weight distribution.

At this size, power-to-weight ratio matters more than outright horsepower. The Zodiac Pro Open 650 2013 comes in at 10 lbs per hp versus 10 lbs per hp for the Zodiac Medline II 2012. 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.

Top speed is rated at 48 mph for the Zodiac Pro Open 650 2013 and 46 mph for the Zodiac Medline II 2012.

Both are inflatable designs, which means they pack down for compact storage, can be carried in a bag, and are dramatically lighter than equivalent rigid hulls. The trade-off is setup time and the need to monitor tube pressure regularly. Tube diameter differs: 1 ft. 11 in. (0.575 m) on the Zodiac Medline II 2012 vs 1 ft. 10 in. (0.57 m) on the Zodiac Pro Open 650 2013 — larger tubes generally mean more buoyancy and a drier, more stable ride.