The following is a summary of how to use this facility in a series of analyses of a system that includes a CALM buoy. Firstly, you include the buoy directly in your model with an assemblage of standard beam-column elements. The geometric properties you assign to the buoy elements should be such as to make the buoy rigid, and one node of the assemblage should be located at the buoy centre of gravity (CoG). You should suppress drag and buoyancy forces on the buoy elements by specifying zero effective drag and buoyancy diameters for these elements. Likewise the elements should have zero mass and zero polar inertia. You specify data for all of these forces on the buoy separately, and all of these effects are applied at the buoy CoG. The reason why you model the buoy as an assemblage of elements rather than just have one CoG node is so that you can have the risers and moorings lines attached to the buoy in their actual, real-life locations. This allows the effect on the buoy motions of the spatial separation between these connection points to be accurately modelled.
