When two boats share the same hull type — in this case both the Mercury PT850 2008 and the Mercury V-520/570 Series 2009 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?
Size is the most obvious dividing line here. The Mercury PT850 2008 measures 27,0 feet overall (2008), giving it roughly 10,0 additional feet of deck space compared to the Mercury V-520/570 Series 2009 at 17,0 feet (2009). Weight tells a clearer story for trailering families: the Mercury PT850 2008 tips the scales at 2 557 lbs — 1 979 lbs more than the Mercury V-520/570 Series 2009 at 578 lbs. That difference is meaningful if you're working within a half-ton or three-quarter-ton truck's tow rating, especially once you factor in a motor, gear, and fuel.
The power gap is worth calling out. Rated to 500 hp, the Mercury PT850 2008 has a 400-hp advantage over the Mercury V-520/570 Series 2009's 100-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 Mercury PT850 2008 is rated for 26 passengers, while the Mercury V-520/570 Series 2009 caps at 9. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Mercury PT850 2008 could be the deciding factor.
Bottom line: Choose the Mercury PT850 2008 if your priority is putting more people on the water — it handles 26 passengers and at 27,0 ft it has the deck room to back that rating up comfortably. The Mercury V-520/570 Series 2009 is the smarter pick if you want a lighter, easier-to-trailer boat rated for 9 that costs less to run day-to-day.