The Sea Ray SLX 400 2023 vs Sea Ray Sundancer 310 2011 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.
Size is the most obvious dividing line here. The Sea Ray SLX 400 2023 measures 39,6 feet overall (2023), giving it roughly 8,6 additional feet of deck space compared to the Sea Ray Sundancer 310 2011 at 31,0 feet (2011). Weight tells a clearer story for trailering families: the Sea Ray SLX 400 2023 tips the scales at 20 794 lbs — 9 164 lbs more than the Sea Ray Sundancer 310 2011 at 11 630 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 SLX 400 2023 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 25 gallons in the Sea Ray SLX 400 2023. 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 SLX 400 2023 is rated for 12 passengers, while the Sea Ray Sundancer 310 2011 caps at 9. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Sea Ray SLX 400 2023 could be the deciding factor.
Bottom line: Choose the Sea Ray SLX 400 2023 if your priority is putting more people on the water — it handles 12 passengers and at 39,6 ft it has the deck room to back that rating up comfortably. The Sea Ray Sundancer 310 2011 is the smarter pick if you want a lighter, easier-to-trailer boat rated for 9 that costs less to run day-to-day.