Both the Princecraft Vectra 18 2009 and the Princecraft Vectra 18 SF 2010 are pontoon designs, both built in aluminium, so 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 - Princecraft Vectra 18 2009 at 18,0 ft versus Princecraft Vectra 18 SF 2010 at 18,3 ft. At 1 350 lbs and 1 394 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 - 50 hp for the Princecraft Vectra 18 2009 and 60 hp for the Princecraft Vectra 18 SF 2010. 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 Princecraft Vectra 18 SF 2010 is rated for 9 passengers, while the Princecraft Vectra 18 2009 caps at 6. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Princecraft Vectra 18 SF 2010 could be the deciding factor.
One place where both boats are genuinely identical is tube construction: both run 2 aluminum tubes at 23" diameter. That shared spec means stability and buoyancy characteristics are closely matched - the ride difference you'll feel between them comes primarily from deck length, weight distribution, and motor choice.
Bottom line: Choose the Princecraft Vectra 18 SF 2010 if your priority is putting more people on the water - it handles 9 passengers and at 18,3 ft it has the deck room to back that rating up comfortably. The Princecraft Vectra 18 2009 is the smarter pick if you want a lighter, easier-to-trailer boat rated for 6 that costs less to run day-to-day.