Both the Sea Ray 47 Sedan Bridge 2008 and the Sea Ray 580 Sundancer 2011 are semi-displacement designs, both built in fibreglass, so 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 580 Sundancer 2011 measures 60,0 feet overall (2011), giving it roughly 10,0 additional feet of deck space compared to the Sea Ray 47 Sedan Bridge 2008 at 50,0 feet (2008). Weight tells a clearer story for trailering families: the Sea Ray 580 Sundancer 2011 tips the scales at 53 500 lbs - 16 000 lbs less than the Sea Ray 47 Sedan Bridge 2008 at 37 500 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 2011 has a 477-hp advantage over the Sea Ray 47 Sedan Bridge 2008'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 2011 carries 825 gallons versus 530 gallons in the Sea Ray 47 Sedan Bridge 2008. 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 2008 is rated for up to 15 people. Passenger data for the Sea Ray 580 Sundancer 2011 wasn't available.