The Cayman Yachts F580 Flybridge 2021 vs Cayman Yachts S640 Sport 2018 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 Cayman Yachts S640 Sport 2018 measures 65,3 feet overall (2018), giving it roughly 7,4 additional feet of deck space compared to the Cayman Yachts F580 Flybridge 2021 at 57,9 feet (2021). Weight tells a clearer story for trailering families: the Cayman Yachts S640 Sport 2018 tips the scales at 78 264 lbs — 25 353 lbs less than the Cayman Yachts F580 Flybridge 2021 at 52 911 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.

Both boats share a closely matched power ceiling — 800 hp for the Cayman Yachts F580 Flybridge 2021 and 800 hp for the Cayman Yachts S640 Sport 2018. Real-world performance will come down more to which motor is actually bolted on, its load at the time, and whether it's a 4-stroke or 2-stroke setup. Fuel capacity breaks the other way: the Cayman Yachts S640 Sport 2018 carries 964 gallons versus 528 gallons in the Cayman Yachts F580 Flybridge 2021. 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 Cayman Yachts S640 Sport 2018 is rated for 19 passengers, while the Cayman Yachts F580 Flybridge 2021 caps at 17. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Cayman Yachts S640 Sport 2018 could be the deciding factor.