When two boats share the same hull type — in this case both the South Bay 520F 2009 and the South Bay 522FC 2012 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 — South Bay 520F 2009 at 21,0 ft versus South Bay 522FC 2012 at 23,6 ft. At 16 lbs and 18 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.
The power gap is worth calling out. Rated to 150 hp, the South Bay 522FC 2012 has a 60-hp advantage over the South Bay 520F 2009's 90-hp ceiling — enough to notice on acceleration and at cruising speed, particularly with a full passenger load. Fuel capacity breaks the other way: the South Bay 520F 2009 carries 31 gallons versus 27 gallons in the South Bay 522FC 2012. On a lake day that's negligible, but for coastal cruising or long reservoir runs the extra range matters.
Both boats are rated for 12 passengers — a good fit for a family of four or five plus guests. Comfort at capacity is another matter; the longer hull typically means more seat options and better weight distribution.
One place where both boats are genuinely identical is tube construction: both run 2 aluminum tubes at 25" 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: The South Bay 522FC 2012 at 23,6 ft is the right call if deck space, comfort, and entertaining are top of your list. The South Bay 520F 2009 at 21,0 ft wins on trailering ease, likely lower purchase price, and simpler docking — a solid choice for a buyer who wants more boat for less money.