When two boats share the same hull type — in this case both the Zodiac 300 2009 and the Zodiac Pro 500 2010 are inflatable rigid designs with rigid 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?
The power gap is worth calling out. Rated to 70 hp, the Zodiac Pro 500 2010 has a 60-hp advantage over the Zodiac 300 2009's 10-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 Pro 500 2010 is rated for 9 passengers, while the Zodiac 300 2009 caps at 4. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Zodiac Pro 500 2010 could be the deciding factor.
The Zodiac Pro 500 2010 has a documented top speed of 41 mph. Speed data wasn't available for the other model.
Bottom line: Choose the Zodiac Pro 500 2010 if your priority is putting more people on the water — it handles 9 passengers and at 15,4 ft it has the deck room to back that rating up comfortably. The Zodiac 300 2009 is the smarter pick if you want a lighter, easier-to-trailer boat rated for 4 that costs less to run day-to-day.