When two boats share the same hull type — in this case both the Zodiac Pro 550 2010 and the Zodiac Sundream 2009 are inflatable rigid 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?

Both boats share a closely matched power ceiling — 90 hp for the Zodiac Pro 550 2010 and 80 hp for the Zodiac Sundream 2009. 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.

For family outings this is probably the sharpest distinction between the two. The Zodiac Pro 550 2010 is rated for 12 passengers, while the Zodiac Sundream 2009 caps at 1. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Zodiac Pro 550 2010 could be the deciding factor.

The Zodiac Pro 550 2010 has a documented top speed of 42 mph. Speed data wasn't available for the other model.