DVC Ling said that before the handover, Deep Bay was under the administration of MWDIV. However, Deep Bay is now cut into two halves in accordance with the Memorandum of Understanding signed between Guangdong Province and the Hong Kong SAR after July 1, 1997.

Under the agreement, the Guangdong Public Security Bureau is responsible for patrolling and policing the northern part of the new boundary while the southern part of the new boundary is under the jurisdiction of MWDIV.

PSB patrol craft in the vicinity might seem as if they have entered HKSAR waters, but that's only because the boundary in some areas is so close to the Hong Kong coastline. For example, the boundary near the inlet of the Shenzhen River is less that one nautical mile from Tsim Bei Tsui and Sha Kiu Village.

PSB officers are aware of the presence of the new boundary and observe the Memorandum, and no incident of incursion has occurred since the resumption of sovereignty.

On liaison with its Guangdong counterparts, Police Headquarters has regular meetings with the Shenzhen PSB to exchange case results and II intelligence. MWDIV and NTN Region also exchange views on a bi-annual basis with Shenzhen Border Defence Sub-bureau officials on the management of boats coming into Lau Fu Shan to sell fish.

On enforcement, DVC Ling said that anti-illegal immigration remained the main task of MWDIV.

The arrest of IIs made by MWDIV officers decreased in the past two years. In 1995, a total of 551 IIs were arrested. The number has dropped from 287 in 1996 to 247 last year. Most were arrested in Deep Bay.

Illegal immigrants usually arrive Hong Kong by swimming across Deep Bay or by taking a motorised vessel from the mainland.

DVC Ling said that smugglers often use small motorised vessels to transport electrical appliances into the mainland. In turn, they also smuggle unmanifested diesel fuel into Hong Kong for profit.