The South Bay 529CR Upper Deck 2011 vs South Bay 8520CR 2007 comparison sits squarely in the category of decisions where specs alone won't tell the whole story — intended use, storage, and long-term ownership costs all factor in.
The power gap is worth calling out. Rated to 150 hp, the South Bay 529CR Upper Deck 2011 has a 60-hp advantage over the South Bay 8520CR 2007's 90-hp ceiling — enough to notice on acceleration and at cruising speed, particularly with a full passenger load. Both carry nearly identical fuel loads — 31 gal and 29 gal — so range won't be a tiebreaker here.
The South Bay 8520CR 2007 is an inflatable design — lighter, easier to store, and quicker to launch from a beach or dock without a slipway. The South Bay 529CR Upper Deck 2011 is a rigid hull, which typically offers a more confident ride in chop and easier maintenance over the long term.
Bottom line: The South Bay 529CR Upper Deck 2011 at 29,0 ft is the right call if deck space, comfort, and entertaining are top of your list. The South Bay 8520CR 2007 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.