Professor W. D .Chesterman was a specialist in acoustic studies and a pioneer in the application of the science of acoustics for underwater survey work. As early as 1958, Professor Chesterman published an important treatise entitled “An acoustic aid to sea bed survey” in the academic journal Acustica that spurred interest in the application of sound echoes in undersea surveys.
He later moved to Hong Kong to take up the position of Professor of Physics at the University of Hong Kong. His work on acoustics continued, and he urged the Royal Navy in Hong Kong waters to carry out surveys utilising what was then known as the “ASDIC survey system”. Essentially, the system was a magnetostrictive transducer housed in a fish-like body towed from one of the survey ships. The device sent out an oblique fan-shaped acoustic beam to illuminate an area of the bed 800 yards wide parallel to the ship’s course. The echo from the sea bed is received by the transducer and the myriad features of the sea bed are presented on a map-like facsimile record.[22]
In and around 1962, an underwater survey was carried out respectively in Hong Kong waters by Royal Navy survey ships HMS Dampier, HMS Lanton, and HMS Penston, as well the FRV Cape St. Mary that belonged to the Fisheries Research Station of the Government of Hong Kong.[23]
The survey covered important passages within Hong Kong waters, including East Lamma Channel and Shing Shi Mun (Sheung Sze Mun), Tolo Channel, Port Shelter and Rocky Harbour.
One outstanding achievement of this survey was the discovery and marking of an unusually large undersea rock outcrop that could endanger vessels that draw deeper draught. The rock was found in the East Lamma Channel not far off the Tai Tam Peninsula. The outcrop was henceforth named “Chesterman’s Rock” and was marked on Admiralty charts, highlighting local participation in what was essentially naval survey work.
Notes:
Part 2 Chapter 4.4 - The work of Professor Chesterman and his echo-sounder
