The Sea Ray Sundancer 310 2011 vs Sea Ray Sundeck 290 2017 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.
On paper these two are close siblings in the size department — Sea Ray Sundancer 310 2011 at 31,0 ft versus Sea Ray Sundeck 290 2017 at 29,2 ft. Weight tells a clearer story for trailering families: the Sea Ray Sundancer 310 2011 tips the scales at 11 630 lbs — 5 159 lbs more than the Sea Ray Sundeck 290 2017 at 6 471 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 380 hp, the Sea Ray Sundeck 290 2017 has a 120-hp advantage over the Sea Ray Sundancer 310 2011's 260-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 Sundancer 310 2011 carries 125 gallons versus 85 gallons in the Sea Ray Sundeck 290 2017. On a lake day that's negligible, but for coastal cruising or long reservoir runs the extra range matters.
For family outings this is probably the sharpest distinction between the two. The Sea Ray Sundancer 310 2011 is rated for 9 passengers, while the Sea Ray Sundeck 290 2017 caps at 8. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Sea Ray Sundancer 310 2011 could be the deciding factor.
Bottom line: Choose the Sea Ray Sundancer 310 2011 if your priority is putting more people on the water — it handles 9 passengers and at 31,0 ft it has the deck room to back that rating up comfortably. The Sea Ray Sundeck 290 2017 is the smarter pick if you want a lighter, easier-to-trailer boat rated for 8 that costs less to run day-to-day.