When two boats share the same hull type — in this case both the Sea Ray 47 Sedan Bridge 2009 and the Sea Ray 580 Sundancer 2012 are semi displacement designs with fiberglass 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?

Size is the most obvious dividing line here. The Sea Ray 47 Sedan Bridge 2009 measures 50,7 feet overall (2009), giving it roughly 44,7 additional feet of deck space compared to the Sea Ray 580 Sundancer 2012 at 6,0 feet (2012). Weight tells a clearer story for trailering families: the Sea Ray 580 Sundancer 2012 tips the scales at 535 lbs — 160 lbs less than the Sea Ray 47 Sedan Bridge 2009 at 375 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 1 051 hp, the Sea Ray 580 Sundancer 2012 has a 477-hp advantage over the Sea Ray 47 Sedan Bridge 2009's 574-hp ceiling — enough to notice on acceleration and at cruising speed, particularly with a full passenger load. Fuel capacity breaks the other way: the Sea Ray 580 Sundancer 2012 carries 825 gallons versus 53 gallons in the Sea Ray 47 Sedan Bridge 2009. On a lake day that's negligible, but for coastal cruising or long reservoir runs the extra range matters.

The Sea Ray 47 Sedan Bridge 2009 is rated for up to 15 people. Passenger data for the Sea Ray 580 Sundancer 2012 wasn't available.