Royal Navy Police The Royal Navy Police ( RNP ) is the service police branch of the Royal Navy and Royal Marines . Members of the RNP enforce law , discipline , and maintain order as outlined in the Armed Forces Act 2006 . The Royal Navy Police was known as the Royal Navy Regulating Branch until 2007 , when the service was renamed the Royal Navy Police in a change brought about by the Armed Forces Act 2006 . Members are , however , still known as " Regulators " . The RNP subsumed the Royal Marines Police in 2009 , although for operational purposes the majority of the two cadres of personnel are employed within their respective areas of the service . The RNP provide a Troop strength unit of Royal Marines to 3 Commando Brigade to provide policing services as part of the UK Landing force . The motto of the RNP is " Ne Cede Malis " which translates from Latin into English as ' Do not yield to adversity ' or ' Do not give in to evil ' . History . The Royal Navy has always , in one way or another , had the need to maintain order and discipline . When at sea , historically , the Captain was the king ' s representative , his rule was kept by the First Lieutenant who was assisted by a person known as " thee Ship ' s Marshal " , who was supported by a number of Ship ' s Corporals . Ship ' s Marshals were abolished and replaced by the Master At Arms ( M . A . A . ) rate , which was introduced in about 1699 . A tradition that continues right up to the present day . On punishment day , " at six bells in the forenoon watch " , the order was given , " " All hands to witness punishment " " . The master at arms presented the offender to the Captain who questioned him about the offence and then delivered a verdict . The officer of the offender ' s division was asked if he had anything to say in mitigation . If their reply did not satisfy the Captain , he ordered the man ' s punishment . Other than the actual act of flogging ; the M . A . A . was responsible for ensuring that any punishment awarded was carried out . The M . A . A . was also accountable to the Lieutenant at Arms for the duties of the Ship ' s Corporals , the supervision of sentries , the Guard , and training the ship ' s company in the use of small arms . Another duty that the M . A . A performed was , at around 9pm to patrol the ship and check that all lanterns and fires were out , and that no men were intoxicated . Probably an early form of evening rounds . In September 1944 , the Admiralty concluded that the organisation for the maintenance of discipline on shore in the main naval port areas was unsatisfactory . Colonel D H C Shepherd ( Royal Marines ) , previously the Naval Provost Marshal in Malta , carried out a study into the requirement for a Naval Provost organisation . He reported that the system of landing ships ' patrols in major naval base areas was unsatisfactory because the Petty Officers and Leading Ratings in charge , ( however well briefed ) lacked the knowledge and experience to deal with incidents , and being unable to render lucid written reports , avoided taking action wherever possible . The men detailed for patrol disliked the duty intensely believing it to be a form of punishment . The Shepherd report recommended the introduction of a Leading Patrolman rating to become the junior member of the Regulation Branch and borne primarily for provost duties , and the creation of a Provost organisation to operate within the major naval port areas . Admiralty Fleet Order 6681 / 44 of 21 December 1944 implemented the proposals of the Shepherd report . As a result of the Shepherd report , Regulating Branch training , which hitherto had been carried out in the barracks of the main ports , was centralised . In 1945 , a Royal Navy Regulating School was established at Beechwood Camp in Devon to train all regulating ratings and to maintain branch records . In 1946 , the school moved to Fort Wallington near Portsmouth , then in 1947 to in Essex , then in 1948 to HMS " Excellent " where it remained until November 2005 . Initially , the role of the Leading Patrolman was to augment patrols on shore , and assist in regulating duties as necessary . In 1968 Leading Patrolmen were renamed Leading Regulators . In 2007 the Royal Navy Regulating Branch was renamed the Royal Navy Police in a change brought about by the Armed Forces Act 2006 . Role . The work of the RNP encompasses dealing with routine disciplinary matters , investigation of crime , crime prevention , and advice to the command on general security and close protection matters . As such , members of the RNP are employed in both uniformed and plain clothed roles ; on ships , within shore establishments and in 3 Commando Brigade and other Royal Marine units . Individuals posted on ships and within shore establishments are responsible , through their chain of command for : Although members of the RNP are not warranted constables , the force as a whole is subject to inspection by HM Inspectorate of Constabulary , in the same way as the UK ' s civilian police forces . Jurisdiction . Over service personnel . The RNP have jurisdiction over members of the Royal Navy subject to service discipline , as well as having reciprocal powers to deal with service personnel of the other two branches of the Armed Forces ; The British Army and The Royal Air Force . Over Civilians . The RNP have jurisdiction over some civilians in certain circumstances , as defined by the Armed Forces Act 2006 . Organisation . The Royal Navy Police is headed by the Provost Marshal ( Naval ) ( PM ( N ) ) , based at HMS Excellent , Portsmouth , who is responsible for the management of the service , and the assurance of professional standards delivered by the RNP in the course of their duties . RN and RM Policemen are posted on ships and shore establishments with regional headquarters in Portsmouth , Plymouth and Faslane and Special Investigation Branch offices at Portsmouth and Plymouth . Recruiting and training . The Royal Navy Police recruits internally , from within the service , requiring candidates to have reached the trained strength in their initial branch , before serving for four years and qualifying for advancement to Leading Rate or Corporal within that branch . Candidates then undertake a suitability assessment at the Defence College of Policing and Guarding at MOD Southwick Park . On completion of training candidates are rated as Leading Hand , or Corporal . Further professional training is delivered at MOD Southwick Park , or through territorial police forces and is required for later advancement to Petty Officer or Sergeant , Master at Arms ( MAA ) or Colour Sergeant or Warrant Officer Class 1 . Commissioned Officers in the specialisation , are drawn from within , with candidates considered suitable for commissioning via the Senior upper Yardman scheme as officers of the warfare branch of the Royal Navy or as officers of the Royal Marines . Dress . The trade badge for Regulators is a crown ( worn in a wreath by Masters - at - Arms ) .