Design and Construction
The GS 50 was designed by Lazzara himself, and the approach was deliberately conservative. The hull is a solid laminate of multiple layers of mat and woven roving, with full bulkheads and furniture components tabbed in place rather than liner systems. A through-bolted deck joint glassed over from below and a full-length rudder skeg bolted to the hull reflect the straightforward, durable engineering philosophy throughout. The ballast — lead chunks embedded in concrete slurry — is fully encapsulated within the long fin keel, which contributes to a ballast-to-displacement ratio of 30 percent. All tanks are sited below the floorboards, which keeps the center of gravity low and sweetens the motion at sea while also creating useful storage under berths and settees.
The design ratios tell an honest story. A displacement-to-length ratio of 250 places the GS 50 squarely in the moderate-displacement category — stiff enough to carry full cruising stores without degrading performance, yet not so heavy that it demands a gale to move. Ted Brewer's comfort ratio of 38.9 aligns with what experienced offshore sailors expect from a serious blue-water cruising platform: a predictable, settled motion rather than the quick, snappy roll of a lighter racing hull.
Rig and Sailing Performance
The GS 50 was offered in both sloop and ketch configurations, with the ketch adding a mizzen and the option of a mizzen staysail to bring total sail area to approximately 963 square feet. Neither rig is particularly large relative to the displacement — a sail area-to-displacement ratio of 13.4 signals a boat that needs wind to perform. In light air, the choices are to motorsail or to deploy the full inventory of light-weather canvas: spinnaker and mizzen staysail are necessary to maintain good speed below 12 knots of breeze.
When the wind fills in, the picture improves considerably. The boat does not slam in a chop owing to sufficient forefoot bite and deep bilges, and its relatively narrow beam with a moderate hull form means it does not gripe to windward. Most owners report the GS 50 performs best at apparent wind angles of 45 degrees or greater. In moderate to heavy air, sustaining 7 knots under working sail is achievable. One thing to avoid: early aftermarket behind-the-mast mainsail furling systems compromise performance significantly and should be replaced. The wide spreaders and outboard chainplates also limit sheeting angle, so sailors expecting tight upwind performance will need to calibrate their expectations accordingly.
The original 62-hp Perkins diesel is reliable but not quite powerful enough to drive the boat hard into a head sea. The later optional 85-hp Perkins does this job more capably, and a number of boats have since been repowered with turbocharged Yanmar diesels.
Accommodations
The interior is where the GS 50 earns its strongest praise. The most popular three-stateroom charter layout works exceptionally well for families: the master stateroom aft features an en suite head with separate shower and a generous U-shaped double berth that can accommodate a couple sleeping athwartship in harbor or in lateral positions at sea. The forward stateroom has a large V-berth that fills in to form a double and shares a head with the saloon. A third midships stateroom to starboard provides two single bunks with its own small en suite head.
The galley runs as an L-shape down the walk-through passage beneath the center cockpit to port, with twin sinks positioned near the centerline to drain on either tack. The saloon features a dinette to port and a settee with a pilot berth to starboard. Owners who prefer a two-stateroom arrangement gain a wrap-around nav station and expanded engine space beneath the cockpit in place of the midships cabin — a meaningful upgrade for a cruising couple. The three-stateroom layout makes the GS 50 an unusually capable liveaboard or extended-passage platform for its era.
Known Issues
No survey of the GS 50 is complete without an honest accounting of its vulnerabilities. Hull blisters are common and usually cosmetic, but in some cases they involve saturated cavities surrounding the ballast; these must be drained and flushed before filling. The mainmast step — an iron plate in the bilge over the keel — is prone to corrosion and warrants careful inspection. On ketch-rigged boats, the mizzen step may have crushed the deck core beneath it, which calls for probing before purchase. Leaking deck fixtures, hatches, and port windows are other common complaints typical of the era. The bronze stern tube housing the rudderstock can eventually separate from the surrounding hull laminate and requires rebonding when this occurs. Loose tabs around bulkheads and sub-floor structures are another recurring item that owners have had to address.
On the mechanical side, the standard 100-gallon fuel tank is a bit low for long-range passages, and the tank's position low in the boat puts strain on the fuel pump; adding a day tank higher in the boat with a transfer link to the main is a widely recommended upgrade. Factory-installed Onan generators are notorious for reliability problems and are best replaced early.
Refit Priorities
Owners who have invested in their GS 50s have generally found the platform worth the effort. The sequence that makes the most sense: address any ballast-cavity blisters first, then inspect and treat the iron mast step before corrosion progresses, rebond any loose bulkhead tabs and the rudder bronze if needed, and replace the Onan generator. On the rig side, removing any behind-the-mast furling system and restoring a conventional mainsail recovers sailing performance that should never have been compromised. Repowering with a more powerful diesel — the 85-hp Perkins or a modern turbocharged Yanmar — makes the boat significantly more useful as a motor-sailor in light conditions and against steep head seas. Expanding fuel capacity, whether through additional tankage or reliable jerry-can stowage, rounds out the practical upgrades for any serious offshore plan.
The Verdict
The Gulfstar 50 is the best boat Gulfstar ever built, and its longevity on the water validates that judgment. It offers an uncommon combination of spacious, thoughtfully arranged accommodations, a sea-kindly motion in a seaway, and construction that is simple enough for owners to maintain and repair. The known deficiencies are real but largely addressable, and well-maintained examples — which exist in meaningful numbers because owners value their boats enough to make repairs — remain genuinely capable offshore cruisers.
Pros
- Sea-kindly motion; does not slam in a chop and tracks steadily to windward
- Three-stateroom layout is exceptional for families or charter use
- Solid fiberglass hull with tabbed bulkheads; no liner to deteriorate
- Encapsulated ballast and low tankage keep the center of gravity low
- Both sloop and ketch rigs available; ketch adds mizzen staysail option
- Straightforward construction makes most repairs owner-approachable
Cons
- Modest sail plan requires 12+ knots of breeze to perform without supplemental canvas
- Wide spreaders and outboard chainplates limit upwind sheeting angle
- Original 62-hp Perkins diesel is underpowered for driving into a head sea
- Iron mast step is corrosion-prone and requires proactive attention
- Mizzen step may have crushed the deck core on ketch-rigged boats
- Hull blisters can involve saturated ballast cavities in the worst cases
- Standard fuel capacity is low for extended offshore passages
- Factory Onan generators are unreliable and should be prioritized for replacement
