When two boats share the same hull type — in this case both the South Bay 422F A 2013 and the South Bay 520FC TT I/O 2011 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 422F A 2013 at 22,0 ft versus South Bay 520FC TT I/O 2011 at 21,4 ft. At 195 lbs and 234 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 — 115 hp for the South Bay 422F A 2013 and 135 hp for the South Bay 520FC TT I/O 2011. 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 South Bay 520FC TT I/O 2011 is rated for 13 passengers, while the South Bay 422F A 2013 caps at 1. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the South Bay 520FC TT I/O 2011 could be the deciding factor.
Bottom line: Choose the South Bay 520FC TT I/O 2011 if your priority is putting more people on the water — it handles 13 passengers and at 21,4 ft it has the deck room to back that rating up comfortably. The South Bay 422F A 2013 is the smarter pick if you want a lighter, easier-to-trailer boat rated for 1 that costs less to run day-to-day.