When two boats share the same hull type — in this case both the South Bay 420F A 2013 and the South Bay 520CR TT 2009 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 420F A 2013 at 20,6 ft versus South Bay 520CR TT 2009 at 21,0 ft. Weight tells a clearer story for trailering families: the South Bay 420F A 2013 tips the scales at 1 825 lbs — 1 639 lbs more than the South Bay 520CR TT 2009 at 186 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.
The power gap is worth calling out. Rated to 175 hp, the South Bay 520CR TT 2009 has a 85-hp advantage over the South Bay 420F A 2013's 90-hp ceiling — enough to notice on acceleration and at cruising speed, particularly with a full passenger load.
For family outings this is probably the sharpest distinction between the two. The South Bay 520CR TT 2009 is rated for 12 passengers, while the South Bay 420F A 2013 caps at 9. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the South Bay 520CR TT 2009 could be the deciding factor.
Bottom line: Choose the South Bay 520CR TT 2009 if your priority is putting more people on the water — it handles 12 passengers and at 21,0 ft it has the deck room to back that rating up comfortably. The South Bay 420F A 2013 is the smarter pick if you want a lighter, easier-to-trailer boat rated for 9 that costs less to run day-to-day.