I'm South African and my boat is registered in Cape Town and equipped as per SA maritime regulations. I have sailed the French waters and been checked out twice, after the usual passport and visa issues I show them my boat's papers and my SA Yachtmaster Offshore certificate and that's it then on that score, never a mention of ICC. Different story if you want to go up the French rivers and canals, then you need a CEVNI licence and your boat needs a VHF equipped with ATIS.
You will need third party insurance for the marinas.
Check out the visa regulations for the Schengen countries carefully.