Naval Co-operation and Guidance for Shipping (NCAGS) is a naval doctrinal term. Naval personnel are trained to carry out NCAGS establish and provide advice for safe passage of merchant ships worldwide, during times of peace, tension, crisis and war. NCAGS personnel act as a liaison between military commanders and the civil authorities. During war, the NCAGS organization may be responsible for establishing a convoy. NCAGS is used by many NATO countries during exercises such as Bell Buoy. NCAGS has been an important part of the naval reserves.
Previously the doctrinal term used was 'Naval Control of Shipping.'
After 2001, the UK Royal Navy created a naval reserve-manned UK Maritime Trade Operations (UK MTO) office in Dubai to coordinate and exchange information with merchant traffic in the Arabian Sea to help counter Somali piracy.
NCAGS exercises such as Exercise Lucky Mariner test NCAGS skills.
NCAGS can sometimes be confused with AWNIS, which is a completely different set of skills in this area.