Swan 431 Buyer's Guide
The Swan 431 is a Finnish-built Sparkman & Stephens cruiser-racer produced by Nautor from 1976 to 1978, with only 32 hulls completed. On the used market these are scarce, well-found boats whose appeal lies in a serious tall rig, a nine-berth interior, and a substantial lead-ballasted hull. A shopper should understand the layout variants and the few documented wear points before committing.
Layouts on the Used Market
Every Swan 431 shares the same core arrangement: a bow cabin with a double V-berth, two pilot berths in the main cabin, and two aft cabins — one with a double berth to starboard, the other with a single berth to port. The galley is a straight port-side unit just abeam of the companionway, opposite a starboard navigation station, and two heads serve the plan — one aft of the bow cabin to port, one starboard aft. The 100-gallon fresh water capacity and 40-gallon fuel capacity are fixed design figures rather than owner options.
Equipment and Common Upgrades
A transatlantic completion is a commonly fitted attribute among brokerage examples, marking boats with documented ocean-crossing histories rather than local cruisers. Beyond that, the standard Perkins 4.108 diesel of 37 horsepower at 3000 rpm remains the typical auxiliary, supported by a 12-volt, 190-amp-hour service bank. The tall rig's original 150 percent genoa and 1,906-square-foot spinnaker represent the as-designed offshore sail plan rather than a later addition.
What to Inspect
The 431 is a solid fibreglass hull with wood trim; check for gelcoat crazing where the trim meets the deck and for any softening in the 452-square-foot antifouled area below the waterline. The skeg-mounted rudder and swept fin keel are the load-bearing appendages; inspect the skeg-to-hull joint for hairline cracks and confirm the wheel steering carries no free play. The Perkins 4.108 should be started cold to verify the 37-horsepower output at 3000 rpm and to listen for irregular idle that would signal worn mounts. A clean structural survey and a running engine are the principal gates.
Availability and Buyer's Takeaway
United States listings represent the typical market for the Swan 431. A buyer's short checklist:
- Confirm the hull number against the 32-boat production series.
- Inspect the wood trim-to-deck joints for crazing.
- Check the skeg rudder attachment for cracks.
- Start the Perkins cold and verify smooth 3000 rpm.
- Verify the nine-berth layout matches the standard plan.
Price & volume trends
Monthly asking-price and listing-volume trends for the Swan 431. The line shows the median ask each month; the bars show how many listings appeared.
Monthly breakdown · 2 rows
| Month | Listings | Median ask | Δ vs. last mo. |
|---|---|---|---|
| Jul 25 | 1 | $85,000 | — |
| Sep 26 | 1 | $105,000 | +23.5% |
Where they're listed
Swan 431 listings appear across 1 country. United States has the most listings with 1.
Country view
1 listings · 1 country| Country | Median ask | Listings · 12 mo | Active · 90 d | Share |
|---|---|---|---|---|
| United States | $105,000 | 1 | 1 | 100.0% |
Comparable models
Similar length, displacement, and era. Open a row to compare that model's market page.