Mamba 311 Buyer's Guide
Shopping a used Mamba 311 means looking at a Swedish-designed 30-footer from the mid-1980s, with examples built both by BK Marin AB and at other yards. Bengt Karlsson's design pairs a solid fiberglass hull with a lead fin keel, and the compact dimensions — about 30 feet 8 inches overall with a 10-foot beam — make her a manageable coastal cruiser for a couple. Because the build history spans more than one yard, establish who built any specific hull.
Layouts on the Used Market
Expect the usual small-sloop arrangement dictated by the 30-foot length and 53-gallon water against 11-gallon fuel split: a forward berth or saloon conversion, a compact galley, and an aft quarter berth or two. The foam-cored deck and modest wetted surface of about 301 square feet are constants; the variable is finish and wear.
Equipment and Common Upgrades
Evaluate each boat on its own installed gear rather than expect a standard package. Danish waters are the typical market where these boats surface anchor. Prioritize a serviceable Yanmar engine, safe fuel system within the 11-gallon limit, and sound rigging for whichever factory rig the boat carries.
What to Inspect
Check the lead keel-to-hull joint for weeping or voids, verify the fiberglass hull is free of osmotic blistering on the roughly 301-square-foot wetted surface, and inspect the rig — masthead or fractional — for cracked chainplates or fatigued standing rigging. Compare the hull number and construction details against the BK Marin AB standard since yards beyond the original Swedish shop also built the design.
Availability and Buyer's Takeaway
Danish waters are where these boats typically appear. For a viewing, keep a short practical list:
- Establish which yard built the specific hull
- Confirm keel joint integrity and absence of osmosis
- Verify rig type and standing-rigging condition
- Check diesel tank and fuel system within 11-gallon capacity
- Inspect foam-cored deck for soft spots or delamination
Price & volume trends
Monthly asking-price and listing-volume trends for the Mamba 311. The line shows the median ask each month; the bars show how many listings appeared.
Monthly breakdown · 1 row
| Month | Listings | Median ask | Δ vs. last mo. |
|---|---|---|---|
| Jun 26 | 1 | $30,248 | — |
Where they're listed
Mamba 311 listings appear across 1 country. Denmark has the most listings with 1.
Country view
1 listings · 1 country| Country | Median ask | Listings · 12 mo | Active · 90 d | Share |
|---|---|---|---|---|
| Denmark | $30,248 | 1 | 1 | 100.0% |
Comparable models
Similar length, displacement, and era. Open a row to compare that model's market page.
Similar boats to compare
4 similar designs| Model | LOA | Median ask | Listings · 12 mo | Active · 90 d |
|---|---|---|---|---|
| Hanse 311 | 29.49' | $ 43,994 | 25 | 8 |
| Bristol 31.1 | 31' | $ 28,000 | 8 | 4 |
| Beneteau Oceanis Oceanis 311 | 32.25' | $ 43,954 | 4 | 0 |
| Mamba 311You are here | — | $ 30,248 | 1 | 1 |