When two boats share the same hull type — in this case both the Zodiac 310 R 2009 and the Zodiac Cadet Compact 300 2011 are inflatable 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?
Both boats share a closely matched power ceiling — 15 hp for the Zodiac 310 R 2009 and 10 hp for the Zodiac Cadet Compact 300 2011. 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.
Both boats are rated for 4 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.
The Zodiac Cadet Compact 300 2011 has a documented top speed of 21 mph. Speed data wasn't available for the other model.
Bottom line: The Zodiac 310 R 2009 and Zodiac Cadet Compact 300 2011 are closely matched on the specs that matter most. Test-ride both on the water you actually use, check current dealer pricing, and factor in long-term service access before you sign.