The amplified linear motion is converted into rotation using a proprietary cascade gear box, capable of efficient conversion of linear-to-rotating motion with high durability. The cascade gear has a design principle similar to a planetary gear box, dividing a large load onto a multiple of small gears, providing high power density. Compliant elements provide damping of transient loads, making it very robust. A dual set of flywheels/generators provide power absorption and temporary energy storage for power smoothing. Generators and power electronics are standard components known from the wind industry, enabling well known grid connection architecture. The buoys operate autonomously by a programmable logic controller located inside the device, with an interface for remote control and data acquisition to shore over fibre and a radio-link.