You can deregister your boat on a temporary basis, for example while it is undergoing repairs.
Do the following:
Prove your identity
You will always be asked to prove your identity when you visit a registration service point. You can use a passport, an identity card or a Finnish driving licence to do so.
Reason for deregistration and confirmation
Select the reason for deregistration. At the registration service point, you must sign to acknowledge the deregistration.
As confirmation of the deregistration, you will be given a register extract showing your watercraft as having been deregistered.