When two boats share the same hull type — in this case both the South Bay 520F TT 2009 and the South Bay 520F TT 2010 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 TT 2009 at 21,0 ft versus South Bay 520F TT 2010 at 21,7 ft. At 173 lbs and 196 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 — 175 hp for the South Bay 520F TT 2009 and 175 hp for the South Bay 520F TT 2010. 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 — 31 gal and 31 gal — so range won't be a tiebreaker here.
For family outings this is probably the sharpest distinction between the two. The South Bay 520F TT 2010 is rated for 13 passengers, while the South Bay 520F TT 2009 caps at 11. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the South Bay 520F TT 2010 could be the deciding factor.
Both are 3-tube and 2-tube pontoon designs respectively. Tube diameter and gauge affect stability and load capacity — more so than most buyers realize when comparing on paper.
Bottom line: Choose the South Bay 520F TT 2010 if your priority is putting more people on the water — it handles 13 passengers and at 21,7 ft it has the deck room to back that rating up comfortably. The South Bay 520F TT 2009 is the smarter pick if you want a lighter, easier-to-trailer boat rated for 11 that costs less to run day-to-day.