An excellent book on the broader maritime history of the NT is; Northern Voyages: Australia's Monsoon Coast In Maritime History by Dr Alan Powell
The text below is from "A Force Apart?" by Dr Bill Wilson
Shipping was a vital early method of transport in the Northern Territory. One of the earliest tasks allocated to police when Darwin was founded was to check that a light on the jetty continued to burn throughout the night. When the light failed, the police were required to rouse the caretaker to relight it.175
A Water Police section was also established. There is no extant record of the duties this section undertook, but they were probably similar to the Adelaide Water Police, established in 1852 to ‘police the Port Adelaide River, shipping and help the customs department’.176
Police at Borroloola were also affected by shipping after their arrival in 1886.177 Although Borroloola is not on the coast, shipping reached the town via the McArthur River. A small jetty was located at the town. The officer in charge, Mounted Constable Donegan, was appointed as a customs officer in addition to his police duties.178 Donegan was vociferous in his objections to the joint roles, as he considered that his customs duties did not allow him to leave the town and interfered with his policing duties.179 It was August 1888 before a full-time customs officer, W.G. Stretton, a former police officer, arrived in Borroloola. Stretton also became magistrate in the town.180 Police at Borroloola also administered the port, as shown by a letter from the officer in charge to Inspector Waters in 1916 regarding the urgent need to repair the crane on Borroloola’s jetty.181 This involvement with administrative matters was to stand junior police in good stead, as many of those required to deal with administration achieved promotion to higher rank.
A final way in which shipping affected the development of policing was the use of vessels by police to visit the more remote coastal areas almost as soon as the Northern Territory was settled. Inspector Foelsche led the way with many trips aboard the Government launch Flying Cloud and occasionally the steamer Adelaide.182 Without using vessels, many of the sparsely populated areas of the north coast would have been unreachable. Sea transport enabled police to bring the law to the coastal frontiers of the Northern Territory. 173 Manitoba Police Chief to Commissioner Herchmer, 14 August 1887, NAC, RG 18, Volume 22, file 383. 174 Beahen and Horrall. Red Coats on the Prairies, p. 34. 175 Downer. Patrol Indefinite, p. 19. 176 Clyne. Colonial Blue, p. 122. 177 For the first few months, policing in Borroloola was undertaken from the Royal Hotel. Donegan to Foelsche, 7 October 1886, Borroloola Police Station Letter Book, NTAS, NTRS F 275. 178 Donegan to Foelsche 22 May 1888, Borroloola Police Station Letter Book, NTAS, NTRS F 275. 179 Donegan to Foelsche 28 May 1886 Borroloola Police Station Letter Book, NTAS, NTRS F 275. 180 Northern Territory Times and Gazette, 15 September 1888.