Two people have been fined a total of £6,000 by Guernsey’s Magistrate's Court for failing to self-isolate after landing in Sark earlier this month.
The pair arrived in Sark on a private vessel from France and anchored off the island on Tuesday 1 June.
The local authorities were alerted.
By going ashore, they breached COVID-19 regulations.
Between their arrival and their sentencing, the pair - aged 52 and 68 - were self-isolating on their vessel in St Peter Port.
People in Sark are being encouraged to report any suspected breaches of border restrictions to the Sark Constable.
France is classed as a Category 4 country on the Bailiwick's travel list - requiring arriving passengers to isolate until a negative Day 13 test.
Sark has remained Covid-free throughout the pandemic.