When two boats share the same hull type — in this case both the Sea Ray 21 Jet 2013 and the Sea Ray 370 Sundancer 2010 are deep vee 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 370 Sundancer 2010 measures 37,5 feet overall (2010), giving it roughly 16,0 additional feet of deck space compared to the Sea Ray 21 Jet 2013 at 21,5 feet (2013). Weight tells a clearer story for trailering families: the Sea Ray 370 Sundancer 2010 tips the scales at 18 064 lbs — 15 181 lbs less than the Sea Ray 21 Jet 2013 at 2 883 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 375 hp, the Sea Ray 370 Sundancer 2010 has a 255-hp advantage over the Sea Ray 21 Jet 2013's 120-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 370 Sundancer 2010 carries 225 gallons versus 45 gallons in the Sea Ray 21 Jet 2013. 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 370 Sundancer 2010 is rated for 11 passengers, while the Sea Ray 21 Jet 2013 caps at 10. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Sea Ray 370 Sundancer 2010 could be the deciding factor.