Bostrom 31 Buyer's Guide
Shopping a Bostrom 31 on the brokerage market means weighing a Swedish early-seventies design that was built both by Runn Båt AB and as home-completion kits. Several hundred were produced, and the spread in finish quality between a factory boat and a backyard completion is the first thing a buyer should price into any offer. The boat is a masthead sloop with fin-keel options and a documented Yanmar YSB8 diesel, but the used fleet is best judged hull by hull.
Layouts on the Used Market
The Bostrom 31 carries six berths in a roughly 30-foot hull, so expect settee conversions and a quarter berth rather than enclosed staterooms. Because the design was also sold to be home-completed, interior joinery, galley placement, and electrical routing can differ from one boat to the next even when the deck mold is identical. A buyer should not assume a sister ship's layout photo matches the listing in front of them.
Equipment and Common Upgrades
Boats in this market commonly carry a heating system, solar panels, an inverter, radar, AIS, autopilot, chartplotter, EPIRB, and life raft. For a buyer, that cluster means the energy and navigation backbone is usually present: solar and inverter suggest house loads are manageable, while radar and AIS point to coastal or crowded-water use. The presence of a life raft and EPIRB is a sign the prior owner took offshore or extended-trip intentions seriously, worth probing during survey.
What to Inspect
The home-completion history is the dominant inspection theme: a kit hull finished outside the yard can show thin laminate, missed tabbing, or amateur wiring, so check those areas for non-production standards. On iron fin-keel examples, note the keel is made of iron and look for any exterior corrosion or damage at the joint. Confirm which keel is fitted — the shallow fin draws about 1.70 to 1.80 meters and the deeper one about 1.80 to 1.90 meters — and measure actual draft against the claimed option before committing.
Availability and Buyer's Takeaway
These boats typically appear in Germany, Spain, Lithuania, Netherlands, United Kingdom, and Italy.
- Verify whether the hull was factory- or home-completed
- Inspect iron keel for corrosion or damage
- Confirm the fitted keel draft against the listing
- Test the Yanmar YSB8 and shaft drive under load
- Check solar and inverter wiring for amateur joins
Price & volume trends
Monthly asking-price and listing-volume trends for the Bostrom 31. The line shows the median ask each month; the bars show how many listings appeared.
Monthly breakdown · 5 rows
| Month | Listings | Median ask | Δ vs. last mo. |
|---|---|---|---|
| Dec 25 | 1 | $14,567 | — |
| Jan 26 | 1 | $40,561 | +178.4% |
| Feb 26 | 1 | $11,206 | -72.4% |
| Mar 26 | 1 | $38,659 | +245.0% |
| Jun 26 | 1 | $18,910 | -51.1% |
Where they're listed
Bostrom 31 listings appear across 4 countries. Spain has the most listings with 2 (40.0%), followed by Germany and United Kingdom.
Country view
5 listings · 4 countries| Country | Median ask | Listings · 12 mo | Active · 90 d | Share |
|---|---|---|---|---|
| Spain | $39,610 | 2 | 0 | 40.0% |
| Germany | $14,567 | 1 | 0 | 20.0% |
| United Kingdom | $18,910 | 1 | 0 | 20.0% |
| Italy | $11,206 | 1 | 0 | 20.0% |
Comparable models
Similar length, displacement, and era. Open a row to compare that model's market page.
Similar boats to compare
2 similar designs| Model | LOA | Median ask | Listings · 12 mo | Active · 90 d |
|---|---|---|---|---|
| CAL 31 | 31.5' | $ 9,900 | 13 | 0 |
| Boström 31You are here | — | $ 18,911 | 5 | 0 |