The Jeanneau Selection 37 1984 vs Jeanneau Sun Fast 31 1990 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 Jeanneau Selection 37 1984 measures 37,2 feet overall (1984), giving it roughly 11,8 additional feet of deck space compared to the Jeanneau Sun Fast 31 1990 at 25,4 feet (1990). Weight tells a clearer story for trailering families: the Jeanneau Selection 37 1984 tips the scales at 9 039 lbs — 2 205 lbs more than the Jeanneau Sun Fast 31 1990 at 6 834 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 — 18 hp for the Jeanneau Selection 37 1984 and 18 hp for the Jeanneau Sun Fast 31 1990. 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. Both carry nearly identical fuel loads — 10 gal and 13 gal — so range won't be a tiebreaker here.
For family outings this is probably the sharpest distinction between the two. The Jeanneau Selection 37 1984 is rated for 11 passengers, while the Jeanneau Sun Fast 31 1990 caps at 7. If you're regularly pulling extended family or a group of friends onto the water, the extra seats on the Jeanneau Selection 37 1984 could be the deciding factor.
Displacement is where these two sailboats genuinely part ways. The Jeanneau Selection 37 1984 displaces 9 039 lbs — a 2 205-lb difference over the Jeanneau Sun Fast 31 1990 at 6 834 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.
Both boats draw a similar depth — 6,2 ft and 5,8 ft respectively. Marina access and anchorage options should be broadly equivalent between the two.
The Jeanneau Selection 37 1984 uses Sloop rigging.
Hull speed is rated at 7,3 knots for the Jeanneau Selection 37 1984 and 6,7 knots for the Jeanneau Sun Fast 31 1990. For extended cruising, water capacity matters: the Jeanneau Sun Fast 31 1990 carries 26 gallons versus 16 gallons on the Jeanneau Selection 37 1984 — a significant advantage on longer passages where watermaker or provisioning stops aren't guaranteed.
Bottom line: The Jeanneau Selection 37 1984 is the offshore and bluewater choice — at 9 039 lbs displacement and 37 ft it has the load capacity, range, and seakeeping for extended passages. The Jeanneau Sun Fast 31 1990 at 6 834 lbs is the more nimble, accessible option — easier to single-hand and better suited to coastal and inland sailing.