The trials are being held over the weekend in both St Helier and St Peter Port.
“The vessel, the Finalandia DFDS Seaways, will be in St Helier in the morning and will then go to St Peter Port,” said Guernsey Ports.
“These trials have been commissioned by the Governments of Jersey and Guernsey as part of ongoing testing of contingency plans for a number of possible risks, of which supply links naturally form a key part.
“The berthing trials have meant the rescheduling of some of Condor’s services, and we are grateful to them for their cooperation and apologise to everyone who is affected by the disruption.”