845 Naval Air Squadron is a squadron of the Royal Navy Fleet Air Arm. It operates the Westland Sea King HC4 helicopter and provides troop transport and load lifting support to 3 Commando Brigade Royal Marines. A Squadron is a small unit or formation of cavalry, aircraft (including balloons), or naval vessels. ... The Royal Navy of the United Kingdom is the oldest of the British armed services (and is therefore the Senior Service). ... The Fleet Air Arm is the operational group of the Royal Navy responsible for the operation of the aircraft on board their ships. ... For the original Viking use of the name, see Sea-King. ... A helicopter is an aircraft which is lifted and propelled by one or more horizontal rotors consisting of two or more rotor blades. ... 3 Commando Brigade is the main manoeuvre force of the British Royal Marines. ... The Royal Marines (RM), are the Royal Navys elite fighting forces. ...

The squadron is based at RNAS Yeovilton in Somerset. RNAS Yeovilton is an air station of the Royal Navy, sited a few miles north of Yeovil in Somerset. ... Somerset is a county in the south-west of England. ...