The Beneteau Antares 9.80 2005 vs Beneteau First 51 1986 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 Beneteau First 51 1986 measures 51,4 feet overall (1986), giving it roughly 21,4 additional feet of deck space compared to the Beneteau Antares 9.80 2005 at 30,0 feet (2005). Weight tells a clearer story for trailering families: the Beneteau First 51 1986 tips the scales at 28 660 lbs — 19 137 lbs less than the Beneteau Antares 9.80 2005 at 9 523 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 260 hp, the Beneteau Antares 9.80 2005 has a 180-hp advantage over the Beneteau First 51 1986's 80-hp ceiling — enough to notice on acceleration and at cruising speed, particularly with a full passenger load. Fuel capacity breaks the other way: the Beneteau First 51 1986 carries 185 gallons versus 106 gallons in the Beneteau Antares 9.80 2005. 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 Beneteau First 51 1986 is rated for 15 passengers, while the Beneteau Antares 9.80 2005 caps at 9. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Beneteau First 51 1986 could be the deciding factor.

Displacement is where these two sailboats genuinely part ways. The Beneteau First 51 1986 displaces 28 660 lbs — a 19 137-lb difference over the Beneteau Antares 9.80 2005 at 9 523 lbs. That gap separates two entirely different categories of sailing: the heavier boat is built for offshore passage-making and load-carrying, while the lighter hull rewards performance sailing and easier handling in lighter air.

Draft is a practical consideration that many buyers underestimate until they're already at the marina. The Beneteau First 51 1986 draws 9,2 ft, compared to 2,7 ft for the Beneteau Antares 9.80 2005. That 6,5-foot difference affects which anchorages you can access, which haul-out facilities will take you, and how carefully you need to read the tide tables in shallower cruising grounds.

For auxiliary power the Beneteau Antares 9.80 2005 carries a 260-hp engine against 80 hp on the Beneteau First 51 1986. Motoring range and ability to punch through a foul current or enter a tight marina under power will favour the more powerful installation.

For extended cruising, water capacity matters: the Beneteau First 51 1986 carries 74 gallons versus 25 gallons on the Beneteau Antares 9.80 2005 — a significant advantage on longer passages where watermaker or provisioning stops aren't guaranteed.