Design and Naval Architecture
The SEVENTY 7 is a semi-custom design, which means owners can personalize each living space to a degree rarely available in production boatbuilding. The hull is 78 feet, 2 inches overall with a 36-foot, 1-inch beam, dimensions that produce on-deck proportions described by one reviewer as the size of a tennis court. Despite that footprint, the boat reads as proportionate rather than overwhelming. Three distinct outdoor social zones — the aft cockpit with seating for twenty guests, the shaded forward cockpit, and the flybridge — give the boat a layered quality reminiscent of Mediterranean superyacht architecture. The transoms are separated by an optional hydraulic swim platform that lowers below the waterline to recover a tender or serve as a teak beach, a feature that has become something of a signature detail on the model. CNB's background building prestigious custom aluminum racing yachts beginning with designs like Mari Cha II informs the structural sophistication behind what reads as a luxury product.
Rig and Sailing Performance
A 120-foot carbon mast carries 3,609 square feet of upwind sail area, dominated by a square-top mainsail whose foot clears the water by more than 20 feet. Three headsail options on hydraulic furlers — a genoa, an optional staysail, and an optional Code 0 — allow the crew to tune the sail plan to conditions without leaving the working cockpit. Five Harken winches and multiple rope clutch arrays are all led to the cabin-house rooftop, positioned so that multiple crew can work the lines without interfering with the helmsman. Standard propulsion relies on twin 180 HP diesel engines, though the first hull was upgraded to 230 HP John Deere engines with V-shafts. Under power the boat makes approximately 9.2 knots; under sail on a beam reach in 20 knots of breeze, she reaches 12 knots of boat speed. The manufacturer rates an upwind sail area of 335 square meters, with an optional asymmetric spinnaker extending that to 448 square meters.
Accommodations and Interior Layout
The interior is where the SEVENTY 7 leaves the production catamaran world entirely behind. The main saloon is entered through a wide, electrically-operated mirrored sliding-glass door and is level with the cockpit, eliminating the step-down common on smaller cats. A dining table for eight, a U-shaped settee, and a central bar surrounding the mast give the saloon a superyacht quality. Lagoon's signature vertical windows wrap the entire deck level. Belowdecks, the layout accepts three to six cabins plus crew quarters, and the port hull cabins can be configured as a massage room, theater, playroom, or conference room — a degree of flexibility that reflects the boat's semi-custom DNA. The 215-square-foot galley in the port hull is staffed with full-sized household appliances and includes a crew dinette with direct access to the crew quarters. The master stateroom in the forward starboard hull accounts for 377 square feet of dedicated owner space, including a king-sized bed, walk-in closet, desk, sofa, and a head with double vanity. Its most celebrated feature is an optional hydraulic veranda — a teak platform that folds out from the hull itself, opening a private terrace exclusively accessible from the master cabin. The feature drew crowds at its Miami debut and remains one of the most talked-about details of any production catamaran interior.
Known Issues and Cautions
The boats.com first-look review noted one immediately practical concern: the grey oak Wenge flooring on hull number one was extremely slippery, causing visitors to skid even at a steady dock with bare, dry feet. For a boat frequently crewed and chartered across open water, sole texture deserves close attention on any specific hull. The same review also pointed out that the so-called "owner's private saloon" forward is not meaningfully separated from the main saloon, making the manufacturer's marketing language around privacy somewhat misleading — it functions better as overflow seating. The boat is built on the assumption that professional crew will always be aboard; Lagoon itself acknowledges this. Buyers considering private ownership without dedicated crew should evaluate the deck layout and line management against their actual sailing program.
Refit and Customization Scope
Because the SEVENTY 7 is a semi-custom build, each hull can be personalized at the shipyard in meaningful ways — not merely in upholstery or finishes, but in structural cabin arrangements. The flybridge alone can be specced as open space with owner-selected furniture, an integrated sunpad, or a configuration including an optional hot tub, following a trend borrowed directly from the superyacht sector toward non-fixed deck furniture that can be reconfigured based on entertaining needs. An outdoor galley module allows the crew to prepare and serve meals on the flybridge without running below, a practical detail on a boat regularly hosting large groups. CNB's background in building big custom composite yachts means the yard has the tooling and process discipline to accommodate significant owner-specified changes without the ad-hoc quality that plagues retrofits on less sophisticated platforms.
The Verdict
The Lagoon SEVENTY 7 is the rare production catamaran that can credibly compete with custom builds in the same size range. VPLP's naval architecture delivers a structured, capable sailing platform; CNB's construction pedigree provides confidence in long-term structural integrity; and Nauta Design's interior work produces accommodations that put most charter yachts to shame. The owner's veranda alone is worth the conversation. For buyers entering this category, the SEVENTY 7 offers something genuinely uncommon: superyacht amenity and semi-custom flexibility, backed by Groupe Beneteau's industrial support network.
Pros
- 377-square-foot master stateroom with optional hydraulic veranda, among the most generous owner accommodations in the production catamaran market
- Semi-custom layout flexibility allows cabin arrangements from 3 to 6 staterooms plus a crew suite
- Three distinct outdoor social spaces across aft cockpit, forward cockpit, and flybridge
- 3,609 square feet of upwind sail area on a 120-foot carbon mast, with hydraulic furling systems for short-handed management
- Built by CNB, a superyacht-capable shipyard with composite construction expertise
- Hydraulic swim platform at the transoms doubles as tender recovery and beach club
Cons
- Requires professional crew for most practical sailing and entertaining scenarios — genuinely difficult to manage privately without experienced hands aboard
- Slippery cabin sole material documented on early hulls warrants careful inspection and possible replacement
- The "owner's private saloon" is not meaningfully separated from the main saloon despite marketing language suggesting otherwise
- At 78 feet, port access, dockage fees, and logistics in many cruising grounds will restrict itinerary options
- Customization depth means each hull is different — pre-purchase surveys need to account for owner-specified deviations from standard spec
