Seafarers
Seafarers from the EU and EEA countries and Switzerland who work on board a vessel carrying the Finnish flag are usually entitled to benefits regardless of whether they are permanently resident in Finland. One requirement for entitlement to benefits is that the wage amounts to at least EUR 726.27 per month (in 2021).
If you move to Finland but you work on board a vessel carrying the flag of another EU or EEA country, the flag state is responsible for the social security benefits. In such a case, you are usually not entitled to Kela benefits even when you are permanently resident in Finland. If you live in Finland and the company that pays your wage is also headquartered here, you can receive benefits from Kela even if you work on board a vessel carrying the flag of another Member State. You have to apply for an A1 certificate with the Finnish Centre for Pensions (Eläketurvakeskus).
Seafarers from some other country than an EU or EEA country, Switzerland or a country that has a social security agreement with Finland become entitled to Kela benefits if they take up permanent residence in Finland.
Source: KELA 4