The Beneteau First 51 1986 vs Beneteau Oceanis 500 1987 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.

On paper these two are close siblings in the size department — Beneteau First 51 1986 at 51,4 ft versus Beneteau Oceanis 500 1987 at 50,2 ft. Weight tells a clearer story for trailering families: the Beneteau Oceanis 500 1987 tips the scales at 30 865 lbs — 2 205 lbs less than the Beneteau First 51 1986 at 28 660 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 — 80 hp for the Beneteau First 51 1986 and 80 hp for the Beneteau Oceanis 500 1987. 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 Beneteau First 51 1986 carries 185 gallons versus 148 gallons in the Beneteau Oceanis 500 1987. On a lake day that's negligible, but for coastal cruising or long reservoir runs the extra range matters.

Both boats are rated for 15 passengers — a good fit for a family of four or five plus guests. Comfort at capacity is another matter; the longer hull typically means more seat options and better weight distribution.

Displacement is where these two sailboats genuinely part ways. The Beneteau Oceanis 500 1987 displaces 30 865 lbs — a 2 205-lb difference over the Beneteau First 51 1986 at 28 660 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 5,1 ft for the Beneteau Oceanis 500 1987. That 4,1-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.

The Beneteau First 51 1986 uses Sloop rigging.

Hull speed is rated at 8,9 knots for the Beneteau Oceanis 500 1987 and 8,8 knots for the Beneteau First 51 1986. For extended cruising, water capacity matters: the Beneteau Oceanis 500 1987 carries 275 gallons versus 74 gallons on the Beneteau First 51 1986 — a significant advantage on longer passages where watermaker or provisioning stops aren't guaranteed.