Both the Premier Boats Cast-A-Way 231 2007 and the Premier Boats Cast-A-Way 251 2013 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 - Premier Boats Cast-A-Way 231 2007 at 23,0 ft versus Premier Boats Cast-A-Way 251 2013 at 25,4 ft. Weight tells a clearer story for trailering families: the Premier Boats Cast-A-Way 251 2013 tips the scales at 2 950 lbs - 600 lbs less than the Premier Boats Cast-A-Way 231 2007 at 2 350 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 - 140 hp for the Premier Boats Cast-A-Way 231 2007 and 150 hp for the Premier Boats Cast-A-Way 251 2013. 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. Both carry nearly identical fuel loads - 28 gal and 28 gal - so range won't be a tiebreaker here.
For family outings this is probably the sharpest distinction between the two. The Premier Boats Cast-A-Way 251 2013 is rated for 13 passengers, while the Premier Boats Cast-A-Way 231 2007 caps at 12. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Premier Boats Cast-A-Way 251 2013 could be the deciding factor.
Bottom line: Choose the Premier Boats Cast-A-Way 251 2013 if your priority is putting more people on the water - it handles 13 passengers and at 25,4 ft it has the deck room to back that rating up comfortably. The Premier Boats Cast-A-Way 231 2007 is the smarter pick if you want a lighter, easier-to-trailer boat rated for 12 that costs less to run day-to-day.