The Skoog Harvester (formally designated AWEV — Autonomous Wave Energy Vessel) is the functional application of the S.K.O.O.G. architecture (Skoog Kinetic Orbital Oscillating Generator). It is a zero-fuel, zero-emission autonomous cargo vessel that converts the kinetic energy of ocean waves and shallow subsurface currents directly into electrical propulsion — without burning any fuel.

The vessel is not a retrofit of a conventional ship. It represents a fundamentally different category: a mobile wave-energy harvesting platform that also transports cargo, designed for slow-speed, non-time-sensitive ocean routes where predictable logistics and zero-emission operation are prioritised over maximum transit speed.

S.K.O.O.G. (Skoog Kinetic Orbital Oscillating Generator) is the overarching engineering framework within which the Skoog Harvester is the primary vessel application. The architecture converts the orbital particle motion of surface gravity waves — plus steady surface currents in major ocean gyres — into continuous zero-emission propulsion via multi-depth turbine arrays installed in internal hull channels.

Within this framework, the Skoog Open Marine Technology (SOMT) initiative facilitates the development and open-source sharing of all component innovations. Each subsystem — LFAS, IAKKS, PHST, DALAS — is developed as a standalone technology with independent applications beyond the vessel itself.

The hull is designed as a wave-permeable structure. Sea waves pass freely through dedicated internal energy channels running through the hull. Inside these channels, Skoog LFAS turbines (Lift-force-optimized Archimedes Screws) convert the bidirectional orbital wave flow into continuous rotational energy, which is then converted to electricity and supplied to dedicated propulsion units.

Unlike conventional turbines that only extract energy from one flow direction, the LFAS geometry — based on continuously twisted hydrofoil blade profiles — generates positive torque during both phases of the wave’s orbital motion (forward and backward stroke). This eliminates the traditional stop-effect and enables uninterrupted energy extraction.

The channels are arranged at multiple vertical depths: upper rows interact with high-energy wave crests, while deeper rows harvest stable subsurface currents and residual orbital flow beneath the wave field. This multi-depth strategy makes the vessel a hybrid energy system operating on two independent flow sources simultaneously.

Skoog LFAS (Lift-Force-Optimized Archimedes Screw) is the primary energy conversion component. Unlike a conventional Archimedes screw with constant helical pitch, the LFAS features a continuous radial twist — a gradual blade angle variation α(r) from centre (high α) to periphery (low α) — which maintains a near-constant lift coefficient (Cl ≈ 1.2) despite the varying flow velocities that occur across the spiral radius in oscillating wave channels.

This geometry allows the turbine to generate net positive torque across both orbital wave phases through an asymmetric lift response, rather than relying on unidirectional flow. The LFAS is manufacturable via 5-axis CNC machining or carbon-fibre reinforced polymer (CFRP) composites. The calculated local lift-based efficiency is Cp ≈ 0.5–0.6 at the turbine level; system-level power coefficients are conservatively estimated at Cp ≈ 0.35–0.40 for this research phase.

The Skoog Tacking Principle is a novel hydrodynamic navigation method that eliminates the need for a conventional rudder. Instead of using a rudder as a drag-inducing brake to change direction, the system uses two independent Azimuth-DALAS propulsion units — one at each bow of the submerged module — to create a coordinated torque couple.

This positions the hull at an optimal 30–40 degree attack angle relative to the wave field, allowing the vessel to continuously ”crab” — keeping its heading decoupled from its track. The result is that the internal turbine ducts remain optimally aligned with the orbital wave flux for maximum energy extraction, even as the vessel executes strategic tacks toward its destination. The vessel actively navigates for wave energy rather than against it.

The vessel’s submerged cargo module acts as a hydrodynamic keel — analogous to a sailing boat’s keel — providing the lateral resistance that prevents the hull from simply drifting with the waves and forces the wave energy to discharge through the turbine channels instead.

Based on a defined 25-turbine array configuration (10 m diameter turbines, total active swept area ≈ 1,960 m²), the conservatively estimated net continuous power output under realistic Pacific Ocean conditions is:

A nominal net output of 2–3 MW corresponds to the propulsion requirements of Handysize-class cargo vessels (≈20,000 DWT) operating at energy-optimised speeds of approximately 9–10 knots. These values are intentionally conservative and based on standard actuator disk formulation with a 10% array interaction loss applied.

Cargo is transported in a submerged, ballast-stabilised module suspended approximately 10 metres below the water surface — a depth where wave influence and seaway are substantially reduced. This provides an extremely stable transport environment, protecting the payload from wave impact and reducing roll.

The module functions as active ballast and as the vessel’s hydrodynamic keel. Variable ballast control actively adjusts the vessel’s draft, ensuring the turbine intake ducts are optimally positioned relative to the current significant wave height at all times. At port, cargo containers are handled through vertical internal shafts: one container is lowered while another is lifted, maintaining uninterrupted ballast stability and enabling fast turnaround.

Skoog DALAS (Dynamically Adaptive Lift-force-optimized Archimedes System) addresses a critical bottleneck in wave energy conversion: handling high-impulse energy from heavy seas. When the vessel is struck by a large wave (a slam or impact), conventional systems absorb this as destructive mechanical shock.

DALAS instead converts the potentially destructive impulse into electricity. The LFAS turbine is mounted on low-friction rails and coupled to a Linear Permanent Magnet Generator (LPG). Upon impact, the turbine accelerates linearly in the direction of the wave pulse, enabling dual simultaneous energy extraction from both the continuous rotational motion and the linear kinetic movement. After the pulse, the LPG acts as a motor to gently return the turbine to its starting position for the next wave.

The DALAS geometry is also directly applicable to stationary installations such as tidal channels, gravity-driven water channels, hydropower outlets, and conventional vessel propulsion upgrades.

Skoog PHST (Passive Hydrostatic Stabilization) solves the most critical mechanical challenge in shaftless generator design: maintaining the precise microscopic air gap between rotor and stator required for high electrical efficiency — without electronics, sensors, or active control.

PHST replaces conventional bearings with water-filled hydraulic chambers arranged concentrically around the turbine shaft. The system operates in two stages: primary chambers provide coarse isolation against shaft wobble via an immediate hydraulic counterforce; secondary fine-control chambers provide micro-correction to restore the rotor ring precisely to the centreline. This double feedback functions as the mechanical equivalent of an active magnetic bearing — but is completely passive and self-regulating.

Skoog IAKKS (Integrated Active Ceramic Composite Coating System) is an advanced marine surface coating that addresses three simultaneous challenges: erosion resistance, biological fouling prevention, and structural surface integrity. The system combines three integrated technologies:

• Ceramic wear resistance inspired by brake-pad technology (TiO₂ and ceramic grains in a thixotropic epoxy or polyurethane binder) — resistant to cavitation, sand, ice, and pressure shocks
• Active non-toxic antifouling via an embedded conductive mesh (titanium or nickel-plated carbon fibre) pulsing low voltage (1–10 Hz, 1–12 V) to prevent cell attachment — without toxic paints
• Structural reinforcement that binds the coating to the substrate and prevents crack propagation

The target service life is 20 years without repainting, maintaining a permanently mirror-smooth surface (< 10 µm roughness) to preserve LFAS hydrodynamic efficiency over the full operational lifetime.

Skoog RDG (Wall-integrated Shaftless Generator) is the electrical conversion core. The generator’s stator is integrated directly into the channel wall, while the rotating ring (rotor) is recessed and flush with the channel’s inner surface. This eliminates the gearbox and central hub entirely, reduces turbulence and flow resistance, and enables a completely sealed and maintenance-free enclosure.

RDG is enabled by PHST: without passive hydrostatic stabilization, it would be impossible to maintain the microscopic air gap required for high electrical efficiency at low rotational speeds. The integrated LA-Screw + RDG + PHST combination offers a potential 3–10% higher system efficiency compared to conventional turbine systems.

The Skoog Harvester is designed for non-time-sensitive transport, where a positive energy balance and zero-emission operation are prioritised over minimum distance. An AI-based routing system continuously analyses wave height, direction, and ocean data in real time to navigate for maximum energy availability rather than shortest geographic distance.

The vessel’s symmetrical, bi-directional hull with two identical bows allows operation with equal efficiency in either direction. The AWEV concept is optimised for wave-rich routes such as the North Atlantic and North Pacific, where consistent high-energy sea states provide year-round propulsion.

In conventional naval architecture, large wetted surface area (WSA) increases skin-friction drag and is treated as a penalty. In the S.K.O.O.G. architecture, the logic is deliberately inverted: internal duct surfaces are not passive appendages but active energy collection interfaces.

In the same way a sailing vessel requires a large sail area to collect diffuse wind energy, the AWEV requires a large internal wetted surface to collect the comparatively low energy density of the wave field. The ducts function as collectors rather than brakes. Since power harvest increases with the cube of velocity while friction only increases with the square, the energy-to-friction ratio remains favourable at the vessel’s operational speed of 9–10 knots.

Yes. Beyond cargo transport, the AWEV platform is optimised for use as a mobile offshore energy harvester. The vessel can operate as an autonomous production platform for green fuels or hydrogen, harvesting kinetic energy from both underwater wave orbital motion and consistent ocean currents.

This dual-source approach ensures production remains active even in low-wind conditions, as long as there is movement in the water. The vessel’s ability to navigate to optimal energy zones — rather than remaining stationary — gives it a significant advantage over fixed offshore energy platforms.

The S.K.O.O.G. / Skoog Harvester system is currently at architectural research phase. The following development steps are required to progress toward physical validation:

• CFD simulations of the specific duct and LFAS twist geometry under oscillatory inflow
• Prototype turbine testing under realistic wave conditions
• Detailed characterisation of orbital and subsurface current velocity fields in target ocean regions
• FEM analyses to evaluate RDG structural stiffness and deformations
• Electromagnetic modelling to optimise generator efficiency at low rotational speeds
• Verification of PHST sealing techniques and cavitation tolerance

The architecture is published as an open invitation to the global research community — to engineering schools, research institutes, technical universities, shipyards, and maritime investors — to initiate simulations, prototype development, and independent scientific validation.

The entire S.K.O.O.G. architecture and all associated SOMT systems — AWEV, LFAS, IAKKS, DALAS, PHST, and RDG — are published under Creative Commons Attribution 4.0 International (CC BY 4.0):

• ✅ Free to use, research, and further develop
• ✅ Free for academic, industrial, and commercial applications
• ✅ Free to adapt and build upon

No patents are sought. The explicit goal is to remove economic barriers and accelerate global development toward zero-emission shipping.

• Zenodo (DOI — academic publication): https://zenodo.org/records/17552757
• Website: www.skoogmarine.com/skoog-harvester
• Technical Report (PDF): Available for download via the Zenodo publication above
• Contact for collaboration: goran@skoogmarine.com