2   5  7   11    16    21
    - --- -- ---- ----- ----- ---------
   |X|   |  |YRDP|     |     |         |
    - --- -- ---- ----- ----- ---------
       |  |   |     |     |       |
       |  |   |     |     |       |
       |  |   |     |     |       |_(3)Yaw-Rate Drag Coefficient(E10.0)
       |  |   |     |     |
       |  |   |     |     |_(2)Second Node Number(I5)
       |  |   |     |
       |  |   |     |_(1)First Node Number(I5)
       |  |   |
       |  |   |_Compulsory Data Record Keyword(A4)
       |  |
       |  |_Optional User Identifier(A2)
       |
       |_Compulsory END on last data record in data categoy(A3)

(1)-(2) These node numbers specify the positions defining the 'length' on the geometric center of the structure along which the drag force is integrated.

For ship structures these nodes should be positioned where the longitudinal centerline cuts the waterplane at the bow and stern.

For a structure whose plan section (viewed along the negative Z axis) is more square than a ship, the positions of the nodes (1) and (2) should be at the ends of a horizontal diagonal across the structure.

(3) The yaw-rate drag coefficient is the force per unit length per unit velocity squared where the velocity is that of a side-on current (i.e. a current at right angles to the direction along which its 'length' is defined). A function of this force, together with the local current velocity is integrated along the 'length' of the structure to give the total drag force.

The yaw-rate drag coefficient will depend on the cross sectional shape of the structure which generally varies along the 'length'. As the coefficient is assumed constant it therefore represents an average value.