Islander 40 MS Information, Review, Specs

Sailing Performance & Handling

As a motorsailer, the Islander 40 MS is characterized by its high displacement and a relatively conservative sail plan. The hull features a long fin keel and a skeg-hung rudder, a configuration that provides excellent directional stability and tracking—essential for long-distance passage-making. According to period technical assessments, the boat is not a "pointing" machine; its windward performance is modest compared to the Islander 40 sloop, largely due to its increased windage and heavier displacement.

The ketch rig, which is the most common configuration for this model, allows for easy sail-handling in heavy weather, enabling the crew to "sail under jib and jigger" (the mizzen and headsail) when the breeze stiffens. In light air, the 40 MS typically requires the assistance of its engine to maintain hull speed. Owners often note that the boat feels "stiff," meaning it resists heeling significantly even in a blow, providing a sense of security for less experienced crews. The helm is generally heavy but predictable, lacking the finesse of a performance yacht but offering the "tank-like" reliability expected of a 1970s motorsailer.

Interior Comfort & Variations

The primary draw of the Islander 40 MS is its voluminous, center-cockpit interior, which offers a level of privacy and living space rarely found in 40-footers of its vintage. The center-cockpit layout allows for a true "great cabin" aft, featuring a large double berth and often a private head and shower. A key design triumph is the interior walkthrough connecting the main salon to the aft cabin, which avoids the "split-level" inconvenience found on some other center-cockpit designs where one must go topside to move between cabins.

The main salon is spacious, benefiting from the vessel's generous beam and high freeboard, which translates to headroom that often exceeds 6'4". The galley is typically U-shaped and positioned for security at sea, while the forward V-berth provides a second private stateroom for guests. In terms of variations, while the 40 MS is the most common motorsailer variant, it shares its hull lineage with the Islander 40 "Custom" (a more traditional sloop) and influenced the later Robert Perry-designed Islander 41, though the latter moved toward a more performance-oriented hull shape. The use of warm teak joinery throughout the interior was a hallmark of the Costa Mesa factory, creating a traditional "ship-shape" aesthetic that remains popular today.

Known Issues & Buyer’s Checklist

Prospective buyers of an Islander 40 MS should focus their inspections on the common structural realities of 1970s fiberglass construction.

• Fuel and Water Tanks: Like many boats of this era, Islander often used black iron or aluminum fuel tanks. Over five decades, these are prone to internal corrosion and leaking. Given the boat's layout, replacing these tanks can be a major surgical undertaking involving the removal of cabin sole sections.
• Deck Delamination: The decks are typically balsa-cored. High-stress areas around the chainplates, stanchion bases, and the windlass should be thoroughly sounded for "soft spots" or elevated moisture readings, which indicate that water has bypassed the bedding and compromised the core.
• Chainplates: The Islander 40 MS utilizes heavy stainless steel chainplates. Marine surveyors frequently recommend pulling at least one for inspection, as crevice corrosion can occur where the plate passes through the deck, hidden from view.
• Rudder Port and Skeg: Given the age and displacement, the rudder bushings and the attachment point of the skeg should be checked for play or "slop," which can lead to vibration under power or steering fatigue.
• Osmotic Blistering: While Islander hulls were generally thick, they were produced before the widespread use of vinylester resins. It is common to find osmotic blisters on the hull, though they are usually considered cosmetic unless they have penetrated deep into the laminate.

Community & Resources

Owners of the 40 MS benefit from a surprisingly robust support network, largely centered around the Islander 36 Association. Although the association is named for the smaller model, it serves as the de facto technical repository for almost all Islander models of the 1970s, including the 40 MS. The site hosts original manuals, technical drawings, and a forum where owners discuss specific fixes for the Charles Davies-designed hulls. Additionally, the broader Islander community often organizes "Islander-only" rendezvous in the San Francisco Bay and Southern California, providing a platform for owners to exchange restoration tips and sailing lore.

The Verdict

The Islander 40 MS is a quintessential "mariner’s home," offering a rugged hull and an expansive interior that remains competitive with much newer, more expensive yachts. While it will never win a light-air regatta, its ability to carry a heavy load and provide a safe, dry platform in rough water makes it an excellent candidate for coastal cruising or living aboard.

Pros

• Superior Privacy: The center-cockpit/aft-cabin layout with a walkthrough is a premier configuration for live-aboards or families.
• Robust Construction: The heavy fiberglass layup and skeg-hung rudder offer peace of mind for offshore work.
• Protected Helm: The high cockpit and often-added hard dodgers or biminis provide excellent protection from the elements.

Cons

• Sluggish Performance: High displacement and windage mean the engine is often required to make meaningful progress to windward.
• Maintenance Access: Replacing original tanks or servicing the plumbing in the walkthrough can be labor-intensive due to the tight integration of the cabinetry.
• Age-Related Wear: Systems from the 1970s, particularly electrical wiring and plumbing, likely require a full overhaul if not already updated by previous owners.