The Jeanneau Sun Fast 31 1990 vs Jeanneau Sun Odyssey 319 2017 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 Sun Odyssey 319 2017 measures 32,2 feet overall (2017), giving it roughly 6,8 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 Sun Odyssey 319 2017 tips the scales at 11 244 lbs — 4 410 lbs less 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 Sun Fast 31 1990 and 21 hp for the Jeanneau Sun Odyssey 319 2017. 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 Jeanneau Sun Odyssey 319 2017 carries 26 gallons versus 13 gallons in the Jeanneau Sun Fast 31 1990. 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 Jeanneau Sun Odyssey 319 2017 is rated for 9 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 Sun Odyssey 319 2017 could be the deciding factor.
Displacement is where these two sailboats genuinely part ways. The Jeanneau Sun Odyssey 319 2017 displaces 11 244 lbs — a 4 410-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 — 5,8 ft and 6,1 ft respectively. Marina access and anchorage options should be broadly equivalent between the two.
The Jeanneau Sun Fast 31 1990 uses Sloop rigging. Helm style differs too: the Jeanneau Sun Fast 31 1990 uses a 1 tiller versus a 1 wheel on the Jeanneau Sun Odyssey 319 2017. Wheel helms give better leverage and visibility on larger boats; tillers offer direct feedback and simplicity on smaller ones.
Hull speed is rated at 7,3 knots for the Jeanneau Sun Odyssey 319 2017 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 4 gallons on the Jeanneau Sun Odyssey 319 2017 — a significant advantage on longer passages where watermaker or provisioning stops aren't guaranteed.
Bottom line: The Jeanneau Sun Odyssey 319 2017 is the offshore and bluewater choice — at 11 244 lbs displacement and 32 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.