Ocean Cpa Method.pdf May 2026

The is the estimated position where the distance between two ships (the "own ship" and a "target vessel") reaches its absolute minimum. It is the primary metric used by Watchkeeping Officers to assess the Risk of Collision (ROC) . If the CPA is too small, a collision is possible, requiring immediate maneuvering according to COLREGs . 2. Core Parameters The method relies on two primary mathematical outputs:

The direction of the target's movement relative to the own ship. Ocean CPA method.pdf

): The vector difference between the own ship’s velocity and the target's velocity. The is the estimated position where the distance

Recent research, such as that found on ScienceDirect and ResearchGate , suggests improving basic CPA by: Recent research, such as that found on ScienceDirect

Provides GPS-based data including SOG (Speed Over Ground) and COG (Course Over Ground). 4. Calculation Methodology

The perpendicular distance from the own ship to the target's relative motion line. 5. Advanced Refinements

Modern "Ocean CPA" calculations typically integrate data from two primary systems: