Flag Officer Sea Training

Flag Officer Sea Training (FOST) is a Royal Navy training organisation responsible for ensuring that Royal Navy and Royal Fleet Auxiliary vessels are fit to join the operational fleet. FOST certifies crews and vessels as being sufficiently prepared for any eventuality through rigorous exercises and readiness inspections.

The main training and testing period is called Basic Operational Sea Training (BOST), which typically lasts six weeks. It combines surveys of the physical condition of the ship with tests of the crew's readiness for deployment, including a weekly war-fighting and damage control scenario known as a 'Thursday War'. BOST thus has elements of the US Navy's Board of Inspection and Survey (INSURV) and Composite Training Unit Exercise assessments. When USS Forrest Sherman (DDG-98) underwent a short version of BOST in 2012, comments from her sailors included "I've been through other exercises, inspections, and deployment and this was by far the hardest...It was even more intense than INSURV".

History
FOST has been a world centre of excellence in the Royal Navy for naval basic and advanced operational training since it was established by then First Sea Lord Lord Louis Mountbatten in 1958. Originally operated out of Portland, FOST moved to Plymouth in 1999 and the command changed from Flag Officer Surface Flotilla to Commander-in-Chief Fleet.

As a result of the Royal Navy programme 'Fleet First', FOST became the single command responsible for all sea training. The submarine sea-training organisation came under FOST and surface ship training previously undertaken by Flag Officer Surface Flotilla and the squadron staffs also shifted to FOST.

FOST operates a pair of Eurocopter Dauphin helicopters from Plymouth City Airport to allow its instructors to join vessels with minimal delay during intense training periods. Plymouth Airport closed on 23 December 2011 and the FOST helicopters will operate from HMS Raleigh in Cornwall but be based at Newquay.

As well as training Royal Navy personnel, it has also been an important source of revenue in training foreign naval crews to handle and fight their vessels, with around one third of its work used in this capacity.