MDN 62/2026

SÉCURITÉ

Temporary acoustic and hydrophone monitors in western waters of Hong Kong

ActiveReceived 01 Apr 2026, 00:00 UTC

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MARINE DEPARTMENT NOTICE NO. 62/2026 (Marine Works) Temporary Establishment of Acoustic Monitors and Hydrophone Monitors for Dolphin Survey in the Western Waters of Hong Kong With immediate effect and for a period of approximately 10 months, acoustic monitors and hydrophone monitors will be temporarily established at the following locations (WGS 84 Datum): (A) 22-21.32N 113-53.64E (B) 22-19.73N 113-52.17E (C) 22-20.29N 113-53.90E (D) 22-20.65N 113-55.47E (E) 22-20.16N 113-57.83E (F) 22-18.55N 113-52.55E (G) 22-17.63N 113-52.75E (H) 22-17.40N 113-51.54E 2. The acoustic monitors will be laid at the co-ordinates from (A) to (G). The acoustic monitor is an instrument for collecting dolphin data. It will be fixed to a cubic metal frame of 0.5 metre by 0.5 metre by 0.5 metre on the seabed. The total height of the acoustic monitor and the metal frame above the seabed will be about 1 metre. 3. The hydrophone monitors will be laid at the co-ordinates from (F) to (H). The hydrophone monitor is an instrument for collecting dolphin data. It will be fixed to a concrete block anchor on the seabed. Yellow marker buoys fitted with yellow flashing lights will be laid to mark the positions of the three hydrophone monitors. 4. Laying of the monitors will be carried out by a work boat and a working area of approximately 20 metres around the work boat will be established. One guard boat will provide assistance. Vessels engaged in the works will display signals as prescribed in international and local regulations. 5. The hours of work will be from 0700 to 1900 hours. No works will be carried out on Sundays and public holidays. Vessels employed for the works will not stay in the works locations outside the hours of work. 6. Diving operations for retrieving data from the monitors will be carried out by the work boat in the above locations from time to time. Vessels navigating in the vicinity should proceed with caution and keep clear of the works locations at slow speed, bearing in mind that there are divers working in the locations, and the water depths above these acoustic monitors are reduced. 7. A drawing showing the locations of the monitors is attached to this Notice. This Notice supersedes Marine Department Notice No. 216/2024. Mr. S.F. WONG Director of Marine Marine Department Government of the HKSAR Date: 1 April 2026 Action File Ref.: L/M. No. 35/24 in MD-PD&PS-F01-075-01A-003-P060

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Acoustic and hydrophone monitors for a dolphin survey have been temporarily established at eight positions in the western waters of Hong Kong. Monitors are seabed-mounted (frames and concrete anchors) with three hydrophone positions marked by yellow marker buoys with yellow flashing lights. Works and diving for data retrieval will be carried out by a work boat with a guard boat, establishing an approximately 20 metre working area; hours of work 0700-1900 (no Sundays/public holidays). The notice supersedes Marine Department Notice No. 216/2024.

Type: Survey operations · severity moderate
Feed: Survey operationsAll warnings of this kind on the map, or as an API feed.
Location: Western waters of Hong Kong
Validity: From 01 Apr 2026, 00:00 UTC
With immediate effect and for a period of approximately 10 months. Hours of work will be from 0700 to 1900 hours. No works on Sundays and public holidays.
Activity periods: ? - ? (Daily works 0700-1900 (no Sundays and public holidays); vessels will not stay outside these hours)
Hazards: seabed-mounted acoustic monitors, seabed-mounted hydrophone monitors, marker buoys with flashing lights, work boat and guard boat operations, diving operations, reduced water depth above monitors, working area around vessels
Cancels: Marine Department Notice No. 216/2024

Worked out automatically from the warning text on 30 Sept 2026, 11:17 UTC. It can be wrong: the official warning text is the authority.

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This warning's analysis also has:

Action for mariners
Keep-clear distance
Ships named
Lights and buoys affected
Translations
Nearby lights and rescue centres

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Keywordsdiving operations divers working keep clear of

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