FairKeel → Buyer's guides → Wharram Pahi 31
1976–present · designed by James Wharram + Hanneke Boon · built by Wharram Designs (plans) / owner-built
James Wharram + Hanneke Boon Polynesian-inspired cruising catamaran — the smallest of the Pahi cruising line. Plywood-epoxy stitch-and-glue or strip-plank construction from plans sold by Wharram Designs Ltd (Cornwall, UK); the vast majority of hulls are owner-built by amateurs over multi-year timelines. Open slatted bridge deck (no solid panel), deck-stepped masts supported by lashings rather than chainplates, hulls lashed to crossbeams with synthetic line. Wood-composite hull is repairable anywhere with hand tools, epoxy, and glass cloth — a genuine asset for remote cruising. Intended for cost-effective coastal cruising by a couple or shorthanded crew.
This is a general read on the Wharram Pahi 31 class — informed background, not a verdict on any individual boat. Condition, refit history, and how a particular hull was sailed and stored matter far more than class reputation. Use it to know what to look for; for a read on a specific listing, run a free FairKeel report on that boat.
The highest-risk system on any Wharram. Inspect epoxy hot-coat condition (UV degradation visible as chalking), plywood-stitch joint integrity at hull-bottom and bow seams, glass-sheathing delamination around through-fittings and waterline. Moisture-meter survey of every hull section is mandatory. Builder logs + materials provenance (which plywood grade, which epoxy schedule, hot-coat history) matter enormously — they may not exist for older hulls.
Hulls are joined to crossbeams with synthetic-line lashings, not bolts. The lashing design is intentional (distributes load gradually) but lashings need annual inspection and replacement every 5-10 years depending on UV exposure and line material. A failed lashing offshore is a catastrophic failure mode unique to Wharrams.
Wharram designs use a class-specific rig (gaff-like or soft-wing geometry) not equivalent to a generic sloop. Standing rigging geometry, mast support via lashings, and sail-handling layouts are Wharram-specific. Consult Wharram Designs or experienced Wharram riggers; generic-yard quotes are often inappropriate.
Most Pahi 31s use small outboards (5-15hp) — twin or single, mounted in outboard wells or on transom brackets. Verify configuration on a given hull. Outboard wells in plywood hulls are a moisture-ingress hotspot; inspect surrounding laminate carefully.
This guide is the class. A report is that hull. Paste the listing you're looking at and FairKeel grades every claim in it against what's known about the Wharram Pahi 31 — where the evidence is thin, the red flags worth a second look, the costs likely to land in your first season, and whether the boat suits the plans you describe in a few short questions.
It won't read the photos or put a number on the boat — that's the Deep-Dive, and for the real answer, a surveyor. It will tell you when a Deep-Dive isn't worth buying. Free, no account, usually a minute or two.
Run a free report on your listing →Other people's videos, not ours, and not endorsements — walkthroughs and reviews of this class that are worth watching before you look at one in person.
See something that doesn't look right? We'd love to know — email us about the Wharram Pahi 31 →