A High-Density Polyethylene (HDPE) marine boom includes an elongated generally cylindrical shell including an inner layer and an outer layer formed from HDPE with the same formulation, with the inner layer including at least 2% carbon black by mass and the outer layer not including carbon black. The outer layer includes a colorant with ultraviolet stabilizers and the inner layer does not include the colorant. The inner layer is thicker than the outer layer and has been coextruded to form a unitary body. First and second caps formed from the same material as the outer layer are fusion welded to the shell across the full thickness and around a full circumference of first ends and second ends of the shell and form a watertight seal. A floatation billet is in the shell.

A High-Density Polyethylene (HDPE) marine boom includes an elongated generally cylindrical shell including an inner layer and an outer layer formed from HDPE with the same formulation, with the inner layer including at least 2% carbon black by mass and the outer layer not including carbon black. The outer layer includes a colorant with ultraviolet stabilizers and the inner layer does not include the colorant. The inner layer is thicker than the outer layer and has been coextruded to form a unitary body. First and second caps formed from the same material as the outer layer are fusion welded to the shell across the full thickness and around a full circumference of first ends and second ends of the shell and form a watertight seal. A floatation billet is in the shell.

A marine boom system includes at least one HDPE marine boom with an axial passage for mounting on a chain and a chain stop. The boom includes a shell defining a cavity with watertight caps having central apertures on the ends. An axial passageway pipe is disposed longitudinally along a center axis, and extends through the apertures and beyond the ends of the shell. A floatation billet is disposed within the shell. A chain is disposed in the axial passageway pipe and extends beyond the ends of the axial passageway pipe. The stop including at least one assembly piece may be fastened to the chain and disposed within an end of the pipe. The assembly piece includes a semi-cylindrical main body with passageway formed therein and has a protrusion about one passageway and a recess about another. A flange and a link saddle extend from the main body.

A marine boom system includes at least one HDPE marine boom with an axial passage for mounting on a chain and a chain stop. The boom includes a shell defining a cavity with watertight caps having central apertures on the ends. An axial passageway pipe is disposed longitudinally along a center axis, and extends through the apertures and beyond the ends of the shell. A floatation billet is disposed within the shell. A chain is disposed in the axial passageway pipe and extends beyond the ends of the axial passageway pipe. The stop including at least one assembly piece may be fastened to the chain and disposed within an end of the pipe. The assembly piece includes a semi-cylindrical main body with passageway formed therein and has a protrusion about one passageway and a recess about another. A flange and a link saddle extend from the main body.

A marine boom system includes at least one HDPE marine boom with an axial passage for mounting on a chain and a chain stop. The boom includes a shell defining a cavity with watertight caps having central apertures on the ends. An axial passageway pipe is disposed longitudinally along a center axis, and extends through the apertures and beyond the ends of the shell. A floatation billet is disposed within the shell. A chain is disposed in the axial passageway pipe and extends beyond the ends of the axial passageway pipe. The stop including at least one assembly piece may be fastened to the chain and disposed within an end of the pipe. The assembly piece includes a semi-cylindrical main body with passageway formed therein and has a protrusion about one passageway and a recess about another. A flange and a link saddle extend from the main body.

A marine boom system includes at least one HDPE marine boom with an axial passage for mounting on a chain and a chain stop. The boom includes a shell defining a cavity with watertight caps having central apertures on the ends. An axial passageway pipe is disposed longitudinally along a center axis, and extends through the apertures and beyond the ends of the shell. A floatation billet is disposed within the shell. A chain is disposed in the axial passageway pipe and extends beyond the ends of the axial passageway pipe. The stop including at least one assembly piece may be fastened to the chain and disposed within an end of the pipe. The assembly piece includes a semi-cylindrical main body with passageway formed therein and has a protrusion about one passageway and a recess about another. A flange and a link saddle extend from the main body.

A waterborne barrier which includes an elongate array of buoys which are connected together by tamper-proof couplings, wherein each buoy has a buoyant body which is rotatable about a central axis and which is formed from expanded plastics material in a circular cylindrical plastics shell, with a reinforcing structure embedded in the plastics material.

A waterborne barrier which includes an elongate array of buoys which are connected together by tamper-proof couplings, wherein each buoy has a buoyant body which is rotatable about a central axis and which is formed from expanded plastics material in a circular cylindrical plastics shell, with a reinforcing structure embedded in the plastics material.