Seven dive groups have permission to explore the seabed of St Peter Port's Harbour on Christmas morning.
Diving in St Peter Port Harbour is only possible on Christmas Day, with prior permission from the Harbourmaster.
For some, searching for fresh scallops and old artefacts on 25 December has become a festive tradition.
A 3rd Century Gallo Roman shipwreck known as ‘Asterix’ was famously discovered by local diver Richard Keen at the harbour entrance in 1982.
This year, 28 have applied to dive around the Pierheads, from 8AM till midday.
Head of Port Operations Jerome Davis says safety is a priority.
"Christmas Day is the only day on which diving by organised groups can be carried out safely in the designated harbour areas.
I would like to thank our staff who will be providing cover for the hyperbaric chamber at the Princess Elizabeth Hospital should the need be required.”
All divers are required to have a surface marker buoy and be accompanied by a support vessel with marine VHF Radio monitoring Guernsey VTS (channel 12) at all times.

Annual Navy commemoration service in Guernsey
Information session ahead of Guernsey parish elections
Work on broken sewer off Guernsey's east coast set to begin
Ministers meet to discuss Channel Islands connectivity
Guernsey vinery used in drug operation
Ban for Guernsey supporter cautioned over Muratti trouble
Guernsey gets hooked on fresh fish
Brittany Ferries yet to open winter Guernsey-Portsmouth bookings