PROMERC Counter Measure Manoeuvres

There are four counter measure manoeuvres identified in the PROMERC project against suspect vessels and pirates:

• Avoid being detected
• Step aside
• High speed escape
• Delay boarding

The onboard Tactical Decision Aid (TDA) will visualize the manoeuvre advice to the bridge team based on the actual suspect vessel position information received from the VDR (Voyage Data Recorder).

Description of the counter measure manoeuvres against suspect vessels, ‘Avoid being detected’ and ‘Step aside’ is given below.

Avoid being detected
The manoeuvre decision aid must calculate a route around a detected suspect contact, such that:

• the distance between the own vessel and the suspect contact does not become less than the specified avoid being detected safety range;
• the own vessel does not collide with other contacts (i.e., the distance between the own vessel and the other contact does not become less than the specified avoid being detected safety range);
• the own vessel sails around islands/shores, sand banks, and (if possible) high risk areas;
• the maximum acceleration, deceleration and turn rates of the own vessel are taken into account.

Picture ‘Avoid being detected’ : Manoeuvre for a merchant vessel sailing northwards and a suspicious contact sailing west-south-west. The solid blue circle denotes the merchant vessel’s detection range, and the dotted circle the assumed contact’s detection range, which must be avoided.

Step aside
If a suspect contact is on an intercept course with the own vessel, the own vessel must change its course in order to determine the contact’s intention. This course change must be such that no intercept takes place within a certain range. If the suspect contact changes its course such that it can again intercept the own vessel, the contact’s intention is assumed hostile.

The manoeuvre decision aid must calculate a route around a detected suspect contact, such that:

• the distance between the own vessel and the suspect contact does not become less than the specified step aside safety range;
• the own vessel does not collide with other contacts (i.e., the distance between the own vessel and the other contact does not become less than the specified step aside safety range);
• the own vessel sails around islands/shores, sand banks, and (if possible) high risk areas;
• the maximum acceleration, deceleration and turn rates of the own vessel are taken into account.

If the suspect contact responds on the own course change, the contact’s intention can be considered hostile (if the contact is again on an intercept course) or friendly (if the contact does not change course or evades).