Buying a used Sigma: class pedigree with a survey checklist
A used British Sigma is a known quantity in a way few boats of its era can match — one-design classes mean fleets of near-identical sisterships, active class associations, and decades of accumulated knowledge about exactly where these boats age. The buying decision is mostly about which Sigma life you want: the racing one-designs with their class scenes, or the cruising-leaning variants built alongside them. One caution up front: an American "Sigma 18" is a different, unrelated boat — a Florida-built rebadge of the Tangerine daysailer whose maker went bankrupt in 1980 — not a member of the Plymouth-built range.
Which era to target
The Sigma 33 one-designs span hull A3001 to A3364, built from the end of 1978 through 1991, with early boats wearing off-white gelcoat and blue or cream decks and later boats white throughout with aluminium window frames. The 33C cruising variant of the early 1980s trades the racing rig for a shorter masthead setup and a longer, shallower keel. The Sigma 38s run 1985 to 1993, and the roughly seventy Sigma 41s come in masthead and fractional versions. All are Marine Projects builds; the Humphreys-designed Sigma 400 of 1990 stands apart as the only non-Thomas design.
What to inspect across the range
Yachting Monthly's survey guidance on the Sigma 38 doubles as a checklist for a hard-raced fleet: the shroud T-pieces often need reinforcement, the structural matrix around the keel can delaminate after a grounding, the balsa-cored decks can soften, hull-to-deck joints deserve inspection for collision history, and goosenecks wear. On the 33, the near-absence of internal moldings works in a buyer's favor — the hull is unusually easy to inspect. Practical Boat Owner noted the 41 carries a slight built-in list to starboard from its accommodation layout, worth knowing before attributing it to trim or water in the bilge. Racing history is the common thread: these boats were built to be campaigned, so assume the rig and deck hardware have earned their miles.
Navigating the lineup
Choose the 33 or 38 for one-design racing with class support, the 33C or the larger cruiser-oriented boats for passagemaking on the same pedigree, and the 400 for the range's one modern-design outlier. The full model directory on this page maps the range.
Where they're listed
Sigma listings appear across 11 countries. United Kingdom has the most listings with 63 (59.4%), followed by Grenada and Germany.
Country view
106 listings · 11 countries| Country | Median ask | Listings · 12 mo | Active · 90 d | Share |
|---|---|---|---|---|
| United Kingdom | $23,047 | 63 | 10 | 59.4% |
| Grenada | $59,000 | 8 | 1 | 7.5% |
| Germany | $52,450 | 6 | 1 | 5.7% |
| Greece | $57,464 | 6 | 2 | 5.7% |
| Netherlands | $52,129 | 6 | 1 | 5.7% |
| Ireland | $21,563 | 5 | 2 | 4.7% |
| Portugal | $64,106 | 5 | 1 | 4.7% |
| Spain | $46,039 | 3 | 2 | 2.8% |
| United States | $59,000 | 2 | 0 | 1.9% |
| Australia | $70,378 | 1 | 0 | 0.9% |
| Curacao | $26,000 | 1 | 0 | 0.9% |
All Sigma models
6 models grouped by length overall. Open any model to see recent asking prices and active listings.
30–40 ft 5 models
40–50 ft 1 model
- Sigma 4115

