Abstract: A wave power converter is presented comprising an airtight compressible bag supporting a ballast and configured to be inflated with gas. The airtight compressible bag comprises flexible walls, wherein the shape and length of the bag is determined by the equilibrium between the weight of the ballast and the pressure inside the bag. A floating body is connected to the airtight compressible bag by a tube. The converter comprises one or more airtight vessels and a power conversion means for generating power from the reciprocating flow of gas between the bag and airtight vessel. The airtight compressible bag is submerged and surrounded by water on all sides wherein the heaving and/or pitching of said floating body excites the oscillation of said ballast which squeezes and expands said airtight compressible bag driving the contained gas via the tube and power conversion means into and out of the airtight vessel.

Abstract: A generally horizontal distensible tube (1) in the sea containing fluid and oriented in the direction of wave travel, the distensibility being chosen so that the propagation velocity of pressure waves inside the tube (bulge waves) is the same as the velocity of propagation of the waves in the sea. Energy is then transferred from the ocean waves to the bulge wave. Energy extraction means (84, 85) at the stern and/or bow convert the bulge power to useful energy. Said energy extraction means may comprise pistons actuating pumps or linear or rotating generators, or one-way valves allowing the bulge wave to pump fluid via hydraulic accumulators through a turbine. The walls of the distensible tube (1) may be comprised partly of elastomer (86) and partly of inelastic flexible polymer coated fabric (87).

Abstract: A generally horizontal distensible tube (1) in the sea containing fluid and oriented in the direction of wave travel, the distensibility being chosen so that the propagation velocity of pressure waves inside the tube (bulge waves) is the same as the velocity of propagation of the waves in the sea. Energy is then transferred from the ocean waves to the bulge wave. Energy extraction means (84, 85) at the stem and/or bow convert the bulge power to useful energy. Said energy extraction means may comprise pistons actuating pumps or linear or rotating generators, or one-way valves allowing the bulge wave to pump fluid via hydraulic accumulators through a turbine. The walls of the distensible tube (1) may be comprised partly of elastomer (86) and partly of inelastic flexible polymer coated fabric (87).