DP capability plot

A DP capability plot is a polar diagram showing the maximum environmental conditions, principally wind speed by direction, in which a dynamically positioned vessel can hold station, presented in the standardized format of IMCA M 140. The plot is drawn in polar form with a wind-speed scale from 0 to 50 m/s and the limiting wind plotted at least every 15 degrees around the hull, with wind, waves, and current assumed coincident and correlated through standard tables. Separate envelopes show the intact case and the worst-case single-failure case after a thruster or power-bus loss, the basis for the DP class notation. The plot is produced from a thruster and power model and verified against sea-trial station-keeping data.