Seabed mapping to update navigational charts
Guernsey's east coast seabed is being surveyed for depths and contours to update electronic map charts.
The survey has been commissioned by Navionics, a manufacturer of electronic navigational charts, and facilitated by Guernsey Ports.
A 6.5 metre Cheetah cat craft called Shoreline is conducting the hydrographic survey with multi-beam equipment, which uses sound waves to map the seafloor.
Guernsey Ports said the survey was expected to take a week and asked mariners to give the vessel, callsign 2EUL9, a wide berth and reduce to a slow speed when passing.
Guernsey's Harbourmaster Captain Jerome Davis said: "Shoreline is visible on Automatic Identification Systems and will be listening to VHF channels 12 and 16 at all times while carrying out survey operations."
He added: "We have asked them to share the survey data with the UK Hydrographic Office so they can also update their products with the latest information".
Follow BBC Guernsey on X and Facebook. Send your story ideas to [email protected].