When two boats share the same hull type — in this case both the Sweetwater SW 1570 FC 2011 and the Sweetwater SW 1780 F3 2008 are pontoon designs with aluminum 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?
On paper these two are close siblings in the size department — Sweetwater SW 1570 FC 2011 at 15,0 ft versus Sweetwater SW 1780 F3 2008 at 17,0 ft. Weight tells a clearer story for trailering families: the Sweetwater SW 1570 FC 2011 tips the scales at 1 835 lbs — 532 lbs more than the Sweetwater SW 1780 F3 2008 at 1 303 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.
Both boats share a closely matched power ceiling — 40 hp for the Sweetwater SW 1570 FC 2011 and 60 hp for the Sweetwater SW 1780 F3 2008. 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 Sweetwater SW 1780 F3 2008 is rated for 8 passengers, while the Sweetwater SW 1570 FC 2011 caps at 7. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Sweetwater SW 1780 F3 2008 could be the deciding factor.
At this size, power-to-weight ratio matters more than outright horsepower. The Sweetwater SW 1780 F3 2008 comes in at 22 lbs per hp versus 46 lbs per hp for the Sweetwater SW 1570 FC 2011. The lower the ratio the more explosive the acceleration — meaningful on a short RIB where bursts of speed, quick planing, and agility in surf or tight waterways define the experience.
Bottom line: Choose the Sweetwater SW 1780 F3 2008 if your priority is putting more people on the water — it handles 8 passengers and at 17,0 ft it has the deck room to back that rating up comfortably. The Sweetwater SW 1570 FC 2011 is the smarter pick if you want a lighter, easier-to-trailer boat rated for 7 that costs less to run day-to-day.