Narai Mk IV Information, Review, Specs

Sailing Performance & Handling

The sailing characteristics of the Narai Mk IV are defined by its deep V-hull sections, which eliminate the need for daggerboards or keels. This design choice simplifies construction and maintenance but results in a higher degree of leeway when sailing close-hauled compared to modern performance multihulls. On a reach or a run, however, the Narai Mk IV excels, often described by owners as having a "motion like a magic carpet." According to technical documentation from Wharram Designs, the hull shape is optimized for sea-kindliness, allowing the boat to slice through chop without the jarring "slamming" associated with flat-bottomed bridge decks.

The sail plan is typically a schooner or ketch rig with low-aspect-ratio sails, keeping the center of effort low to maximize stability. While it lacks the raw sprinting speed of a racing catamaran, its Displacement/Length ratio and high prismatic coefficient allow it to maintain high average speeds over 24-hour periods during ocean passages. Handling is generally considered heavy but predictable; the dual rudders provide sufficient control, though the lack of a central cockpit means the helmsman is often exposed to the elements unless a custom spray hood is fitted to the aft deck.

Interior Comfort & Variations

The interior of the Narai Mk IV is housed entirely within the two narrow hulls, as the bridge deck is an open platform (usually consisting of a slatted deck or heavy-duty netting). This layout offers a unique level of privacy for two couples or a small family, as the hulls are physically separated. The Mk IV version introduced more headroom and beamier hull sections compared to its predecessors, particularly the Mk I and Mk II. Inside, the accommodations are minimalist and functional; one hull typically contains a compact galley and a chart table, while the other is dedicated to sleeping berths and a head.

Sibling models within the Classic range include the smaller 30-foot Tanenui and the larger 46-foot Oro and 51-foot Tehini. While the Narai Mk IV shares the same "Classic" DNA, it is often cited as the "sweet spot" of the range—large enough to carry the stores required for a circumnavigation but small enough for a couple to handle and maintain. Material variations are common, as most Narai Mk IVs were built from marine plywood sheathed in fiberglass and epoxy; however, some later examples utilized more advanced wood-epoxy techniques, which significantly reduced the weight and improved the longevity of the hulls.

Popular Mentions & Media

The Narai Mk IV and its predecessors occupy a legendary space in multihull history, largely due to James Wharram’s own high-profile voyages and his book Two Girls Two Catamarans, which chronicled his early Atlantic crossings. While that book focuses on his earlier designs (Tangaroa and Rongo), the Narai became the commercial backbone of his design office, sold to thousands of builders worldwide. The model is frequently featured in the literature of the 1970s and 80s "back to the sea" movement, and it remains a staple in documentaries focusing on alternative living and low-impact voyaging.

Known Issues & Buyer’s Checklist

Purchasing a Narai Mk IV requires a different set of priorities than a standard production boat, as almost all examples are amateur-built.

• Beam Lashing Integrity: The most critical safety component of a Wharram is the lashing system. Buyers must inspect the synthetic rope lashings for UV degradation and chafe. While inexpensive to replace, neglected lashings can lead to structural failure of the beam-to-hull connection.
• Cross-Beam (Poking-Pole) Rot: The beams are usually hollow box-sections or solid timber. Moisture can become trapped where the beams sit in the hull cradles, leading to localized rot. A thorough sounding of the beams with a phenolic hammer is essential.
• V-Hull Stem Wear: Because these boats are often beachable, the bottom of the "V" at the stem and stern can suffer from abrasion. Check for "thinning" of the fiberglass skin and whether sacrificial "shoes" have been fitted.
• Deck-to-Hull Join: In older Mk IVs, the joint where the deck meets the hull sides can be a source of leaks. Because the boat flexes, traditional sealants may fail; check for staining or soft spots in the plywood interior bulkheads.

Community & Resources

The Narai Mk IV is supported by one of the most dedicated owner communities in the maritime world. The Wharram Builders and Owners Association (WBOA) provides a central hub for technical advice, build logs, and regional meetups. This community is a vital resource for new owners, offering specific guidance on modernizing the rig or implementing the "Tiki-style" lashing upgrades that many Mk IV owners have adopted to improve durability.

The Verdict

The Narai Mk IV is an uncompromising vessel designed for sailors who prioritize seaworthiness and simplicity over marina-side luxury. It is a boat that requires a physical connection to the environment, rewarding its crew with a gentle motion and the security of a time-tested hull form.

Pros:

• Exceptional sea-kindliness and a comfortable motion in heavy seas.
• Simple, robust systems that are easy to repair in remote locations.
• Low draft and beachability allow for exploration of shallow lagoons.
• The "flex" design reduces the risk of structural cracking in the hulls.

Cons:

• Limited windward performance compared to modern multihulls.
• Minimalist interior living space with no central saloon.
• High maintenance requirements for the wooden hulls and lashing systems.
• Amateur build quality can vary significantly between individual boats.