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Mason 33

1984–1989 · designed by Al Mason (Alvin Mason) · built by Ta Shing Yacht Building Co. (Taiwan) — commissioned and imported by Pacific Asian Enterprises (PAE), California

Small heavy-displacement offshore cruiser — the smallest member of the Al Mason / Ta Shing / PAE family. Practical Sailor describes her as "a moderate traditional design that harks back to the CCA handicapping rule of the 1960s... a modern full-keel hull, with a cut away forefoot and sharply turned bilges to reduce wetted surface." Same Pacific bluewater design philosophy as the Mason 43 and Mason 53 (seakindly motion, keel-hung rudder, heavy-laminate construction), scaled down to a couples-friendly platform. Masthead sloop rig — not a cutter (the Mason 43 is the cutter; the 33 is a sloop). Designed for tropical cruising and credible offshore passagemaking in a manageable hull size; not a coastal racer.

This is a general read on the Mason 33 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.

We grade that listing's own claims against what's known about the class, and flag the gaps a survey would catch. Free, no account. No listing yet? See what the free report looks like (a real one, anonymised), or search for a Mason 33 for sale and come back with the link.

At a glance

LOA
33' 9"
Beam
10' 10"
Draft
5' 5"
Hull form
Full Keel
Ballast type
Encapsulated Iron
Rudder
Keel Hung
Mast step
Keel Stepped
Hull construction
Fiberglass
Production
1984–1989
Built in
Taiwan

What the Mason 33 is known for

Known trade-offs

Age-related quirks to expect

Stress cracking at the deadwood-to-hull rounding by year 35-45 (NOT a keel stub — this hull has no fin-keel stub; the relevant zone is the deadwood-to-hull rounding on the full-keel hull) severity: Medium affects: all (age-driven)
Engine progression — early hulls (~1984-86) came with 21hp Westerbeke diesel; later hulls upgraded to 27hp Yanmar three-cylinder. Many hulls now repowered (Beta Marine 25-30 is the common owner pattern). severity: Medium affects: 1984-1989
Encapsulated iron ballast (5,320 lbs, in two pieces taped into the hull molding) — Practical Sailor notes "Americans are more accustomed to lead keels...but iron interior keels are fairly common in the Oriental boats, and we don't hear of many problems." Inspect for keel-sump water + rust signs. severity: Low affects: all (architectural)
Optional teak deck overlay (where fitted) reaching end-of-life by year 30-40 — not all Mason 33s have teak decks; verify per hull. severity: High affects: hulls fitted with optional teak overlay
Original aluminum fuel tank (35 gal capacity) — age-related pitting + leak risk at 35+ years severity: Medium affects: 1984-1989

Systems to check before you buy

Below-WL through-hulls + seacocks priority: offshore, coastal, liveaboard

Original 1980s bronze fittings on a 35-40 year-old full-keel hull. Practical Sailor notes the hull is reinforced in the way of seacocks and each through-hull is identified with a nameplate. Access constraints similar to the Mason 43 — cabin sole or settee removal often required for the deeper bilge fittings, with the labour multiplier compounded by the smaller interior working volume.

Standing rigging + chainplates priority: offshore, coastal

Original wire + tangs typically due at 25-30 years. Chainplates on the Mason 33 are bolted through teak-clad bulkheads (same Ta Shing pattern as the 43) — leak paths around chainplates often hidden behind joinery. Mast is keel-stepped, so mast-step bilge water history matters. Outboard shrouds spread the rig load wide on the deck — inspect deck-edge tie-down hardware carefully.

Engine (early 21hp Westerbeke vs. later 27hp Yanmar 3-cyl vs. repower) priority: offshore, coastal, liveaboard

Practical Sailor verifies the 21hp Westerbeke on early hulls and 27hp Yanmar three-cylinder on later hulls. The 21hp is "probably near the minimum size for the American market" per PS — adequate for offshore work but light on reserve. Many Mason 33s have been repowered with Beta Marine 25-30 or modern Yanmar equivalents; a repowered hull is a meaningful value-add. An original engine at 35-40 years should be assumed near end-of-life unless service records prove otherwise.

Rudder bearing + keel-rudder hinge hardware priority: offshore, coastal

Keel-hung rudder (Practical Sailor: "long keel/attached rudder") hardware wears over decades of offshore use. Service interval is class-known; lift-out inspection of the rudder bearing and the keel-rudder hinge points should be on any pre-purchase survey scope for a 35+ year-old hull.

Hull-to-deck joint priority: offshore, coastal, liveaboard

Inward-turning hull flange with deck resting on top, fastened with through-bolts under stainless flat-bar washers (every other bolt also penetrates the teak toerail). Practical Sailor notes "the only complaint we have heard about the older Masons was some leaking in the hull-to-deck joint, but it's hard to see how the joint could leak on the 33" — the 33's joint design is improved over earlier Mason hulls. Inspect for sealant degradation around genoa-track bolts + toerail bolts at age 35+.

How it fits your plans

Offshore
Designed for it at a smaller scale than the Mason 43. Full-keel motion + masthead sloop rig + heavy displacement (14,020 lbs on 25' 5" LWL) for the size class — credible Pacific / Caribbean platform for couples or single-handers who prefer a manageable hull over the 43's volume. Practical Sailor: "For someone wanting a serious blue water cruiser or a liveaboard boat in her size range, she is the logical choice."
Coastal
Overbuilt for coastal work but a forgiving and easy single-handing platform. Slower than fin-keel boats of the same LOA — windward work is not her forte (outboard shrouds, full-keel hull form). Best with wind slightly ahead of the beam through broad reach.
Liveaboard
Workable for a couple but materially tighter than the Mason 43. Smaller fuel + water tankage limits sustained tropical liveaboard range. Below-WL access constrained by the smaller interior working volume.

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 Mason 33 — 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.

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Video walkthroughs of the Mason 33

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.

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