A method of unloading cargo at sea from a cargo vessel to a cargo barge, comprising the steps of providing a catamaran vessel having a pair of spaced apart catamaran hulls and a pair of spaced apart arch shaped frames, each frame attached to each hull at a frame lower end portion; positioning the cargo vessel in between the hulls and under the top portion of the frames; placing one or more cargo barges next to one or both of the hulls, wherein the hull is in between the cargo vessel and the cargo barge; and unloading cargo from the cargo vessel to the cargo barge wherein the cargo travels from the cargo vessel, over the catamaran hull to the cargo barge.

An ocean-going single-hulled barge with an isolated sunken or recessed area that supports storage vessels and mixing equipment capable of processing, storing and transporting hazardous materials. The recessed area includes dedicated drains which collect all associated hazardous spills and fluids for appropriate disposal and processing. The barge can also be adapted to hold a complete liquid mud plant within the recessed area.

A method of unloading cargo at sea from a cargo vessel to a cargo barge, comprising the steps of providing a catamaran vessel having a pair of spaced apart catamaran hulls and a pair of spaced apart arch shaped frames, each frame attached to each hull at a frame lower end portion; positioning the cargo vessel in between the hulls and under the top portion of the frames; placing one or more cargo barges next to one or both of the hulls, wherein the hull is in between the cargo vessel and the cargo barge; and unloading cargo from the cargo vessel to the cargo barge wherein the cargo travels from the cargo vessel, over the catamaran hull to the cargo barge.

A method of unloading cargo at sea from a cargo vessel to a cargo barge, comprising the steps of providing a catamaran vessel having a pair of spaced apart catamaran hulls and a pair of spaced apart arch shaped frames, each frame attached to each hull at a frame lower end portion; positioning the cargo vessel in between the hulls and under the top portion of the frames; placing one or more cargo barges next to one or both of the hulls, wherein the hull is in between the cargo vessel and the cargo barge; and unloading cargo from the cargo vessel to the cargo barge wherein the cargo travels from the cargo vessel, over the catamaran hull to the cargo barge.