Telstra is forced to warn the captains of between 30 and 50 container ships a month that are seen to be travelling too close to the telco’s subsea cable infrastructure paths.

Executive director of international operations and services Darrin Webb said in a blog post that the telco particularly had issues around Singapore and Hong Kong.

Both cities are major landing points for cables in the region, but are also two of Asia’s busiest “and shallowest” container ports, Webb said.

The telco has a dedicated team that uses a ship’s Automatic Identification System (AIS) – which provides an identification number, position, course and speed for each vessel – to determine where each is in relation to subsea cables in the area.

“If a ship gets too close, our team will make a call to the captain so they can adjust their course,” Webb said.

“On average, our team contacts 30 – 50 container ships a month.”

Webb said the telco also used other methods to protect its subsea infrastructure in the region.

These included employing “out of season fishing crews to monitor areas susceptible to regular damage”, thought to be caused by unregulated fishing boats.

He said Telstra had – in some areas – buried cables “up to three metres below the seabed to avoid being hit by anchors”, or had overland cable redundancy in disaster-prone areas, where the impact of earthquakes or typhoons might damage subsea infrastructure.

Submarine cable infrastructure is regularly damaged, though the causes aren't always clear. Last year, there were cuts to both PPC-1 and Basslink.

Update, 2.08pm: Telstra's blog post initially stated that cables were buried up to three kilometres below the seabed. The blog post has since been updated to read metres.