FCDO advice including information on permitted duration of stay and visas for Switzerland: www.gov.uk/foreign-travel-advice/switzerland
There are various sources for information on the latest restrictions in force due to the Coronavirus pandemic:
RYA Covid-19 hub - https://www.rya.org.uk/coronavirus including advice and information for recreational boaters at https://www.rya.org.uk/coronavirus/advice-for-boaters.
Information on entry requirements can be found at https://www.gov.uk/uk-border-control?priority-taxon=774cee22-d896-44c1-a611-e3109cce8eae
For information on the validity of RYA certificates abroad see Evidence of Competence Abroad.
Evidence of competence is required under Swiss law if the vessel has engine power exceeding 6kW or sail area greater than 15m².
A visitor to Switzerland (a person who is residing temporarily in Switzerland) wishing to navigate a foreign (non-Swiss) flagged boat must have an ICC or a national navigation permit which establishes authorisation to navigate that vessel in the vessel's flag state.
A visitor to Switzerland wishing to navigate a Swiss flagged vessel must have an ICC (issued in accordance with Resolution 40) or a national navigation permit.
A Swiss licence is required by anyone who has been living in Switzerland for more than 12 months. Further information can be obtained from the shipping office of the Kanton in which you are resident. Shipping office details are available at https://www.vks.ch/de/heroes/schifffahrtsaemter.
Switzerland is not an EU Member State but it is part of the European Economic Area (EEA)
Part of the Schengen area.
Signatory to the Regional Arrangement Concerning the Radiotelephone Service on Inland Waterways (RAINWAT). Where a VHF is required or is to be used on the inland waterways of RAINWAT signatory countries, the set must be ATIS enabled and vessels must comply with the requirements of the RAINWAT.