The Catenary Anchor Leg Mooring (CALM) or Single Point Mooring (SPM) system is a buoy that performs the dual function of keeping a tanker moored and transferring fluids, from tanker to shore -and vice-versa- via a subsea pipeline, while allowing the ship to weathervane. Providing a simple, economical solution to the challenge of loading and offloading, they are used for a variety of applications, water depths and vessel sizes ranging from small product carriers to Very Large Crude Carriers (VLCC).