The Riviera Yachts 40 Flybridge 2007 vs Riviera Yachts 51 Open Flybridge SII 2009 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 Riviera Yachts 51 Open Flybridge SII 2009 measures 54,0 feet overall (2009), giving it roughly 12,0 additional feet of deck space compared to the Riviera Yachts 40 Flybridge 2007 at 42,0 feet (2007). Weight tells a clearer story for trailering families: the Riviera Yachts 51 Open Flybridge SII 2009 tips the scales at 4 806 lbs — 1 830 lbs less than the Riviera Yachts 40 Flybridge 2007 at 2 976 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 920 hp, the Riviera Yachts 40 Flybridge 2007 has a 95-hp advantage over the Riviera Yachts 51 Open Flybridge SII 2009's 825-hp ceiling — enough to notice on acceleration and at cruising speed, particularly with a full passenger load. Fuel capacity breaks the other way: the Riviera Yachts 51 Open Flybridge SII 2009 carries 977 gallons versus 473 gallons in the Riviera Yachts 40 Flybridge 2007. 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 Riviera Yachts 51 Open Flybridge SII 2009 is rated for 16 passengers, while the Riviera Yachts 40 Flybridge 2007 caps at 13. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Riviera Yachts 51 Open Flybridge SII 2009 could be the deciding factor.