Hull Construction and Deck Integrity
The IP 37's hull is a solid fiberglass laminate with no core material, reinforced by a fiberglass structural grid and plywood bulkheads that are all tabbed in place. This no-core approach in the topsides eliminates one of the most common failure modes in production boats: delamination from water ingress at hardware penetrations. The decks use a different strategy, employing Island Packet's proprietary PolyCore, a resin microsphere composite that resists rot, performs well in compression, and proves less susceptible to delamination than conventional foam or balsa cores.
The hull-to-deck joint receives what one reviewer described as a belt and suspenders approach: adhesive sealant combined with nuts, bolts, and washers at an inward flange. Critically, the mechanical fasteners remain accessible for inspection and service without destroying interior liners — a detail that matters enormously twenty years into a boat's life. Deck hardware is backed with aluminum plates to distribute loads properly. Island Packet backed all of this with a ten-year transferable warranty that covered not only osmotic blistering but delamination of the deck composite — an unusually confident guarantee that extended to second, third, and fourth owners.
Deck Layout and Cockpit
On deck, the IP 37 is organized for offshore work. A diamond-pattern non-skid surface covers the working areas, double lifelines run the full length of each side supported by securely fastened stanchions, and a continuous handrail runs the entire length of the coachroof — a feature that makes moving forward in a seaway considerably safer than the short, interrupted grab rails found on many contemporaries.
The eight-foot cockpit provides full-length seats on both sides, a centerline helm seat aft of the steering pedestal, and a standard drop-leaf table forward of the wheel. A large starboard seat locker handles storage. The layout prioritizes crew comfort on passage over any pretense of racing utility.
Rig, Keel, and Sailing Performance
The IP 37 carries a full keel, available in standard draft at 4'6" or shoal draft at 3'8". The full keel delivers good tracking and reduced leeway for a given draft, and its robustness allows hauling in remote anchorages that lack modern travel-lift facilities — a practical consideration for extended cruising. The tradeoff is increased wetted surface and the frictional resistance that comes with it. Owners report good performance in all but very light air, which is an honest characterization of what a full-keel cruiser with 18,500 pounds of displacement can reasonably deliver.
The sail area-to-displacement ratio warrants scrutiny. Island Packet claimed an SA/D of 18.3 by including the staysail in the calculation; the reviewer's own calculation using the manufacturer's rig dimensions produced a more conservative figure of 15.2, which is the standard comparative number. Prospective owners should use the lower figure when benchmarking against other cruising designs. Stability is genuinely impressive: company literature claims a positive righting moment to more than 140 degrees, with maximum righting moment occurring between 75 and 80 degrees — suggesting a very stiff, self-rescuing hull form.
Interior Accommodations
Below decks the IP 37 offers a forward V-berth cabin, an aft quarter berth cabin, and a central saloon. The galley stands out as a particular strength — one of the best for a boat of this size, with a workable layout suited to cooking at sea. The aft quarter berth provides dedicated sleeping space separated from the saloon.
The one area where the design falls short for offshore passagemaking is dedicated sea berths. The main saloon settees can be fitted with weather cloths for passages, but purpose-built pipe berths or positively shaped sea berths were not part of the standard arrangement. This is a meaningful limitation for offshore passages in any but moderate conditions, though it matters less for the coastal and Caribbean cruising that many IP 37 owners actually pursue.
Engine and Mechanical Access
Auxiliary power comes from a 38 hp fresh-water-cooled Yanmar diesel mounted below the companionway steps in a dedicated engine box. Access for inspection and maintenance is described as quite good, and the engine is appropriately sized for the displacement. Fresh-water cooling extends engine life considerably compared to raw-water-cooled alternatives, and the Yanmar powerplant has a long track record of reliability and parts availability in cruising destinations worldwide.
The Verdict
The Island Packet 37 is exactly what it appears to be: a conservatively designed, solidly built, deliberately focused cruising sailboat. It rewards owners who match their expectations to its character — unhurried, seaworthy, well-finished, and maintenance-friendly over the long haul. Sailors seeking thrilling light-air performance or racing versatility should look elsewhere; those prioritizing build quality, range, and comfort on extended passages will find a great deal to admire.
Pros
- Solid glass hull with no-core topsides eliminates a common delamination failure mode
- Transferable multi-owner warranty covering hull, blisters, and deck delamination
- Superb deck ergonomics: double lifelines, continuous coachtop rail, unobstructed working areas
- Full keel delivers excellent tracking and can haul in remote locations with primitive facilities
- Exceptional righting moment well beyond 140 degrees offers genuine offshore stability
- Outstanding galley for the size, purpose-built for extended cruising
- Fresh-water-cooled Yanmar with good engine-room access
Cons
- Full keel adds significant wetted surface and penalizes light-air performance noticeably
- True SA/D of approximately 15.2 is modest; Island Packet's published figure inflates the comparison
- No dedicated sea berths in the standard arrangement; settees require weather cloths for offshore work
- Standard and shoal draft ballast figures are identical despite different keel geometries, suggesting limited published engineering transparency
