We’ve been looking into the impact of Brexit on our sailing, on the assumption that at some point we will be treated as a third country, just like US and Canadian sailors who cross the Atlantic to visit the EU. If there is a hard Brexit at the end of March, this could all be upon us next season. The result is likely to be a long term increase in paperwork and bureaucracy and a permanent annoyance for British yacht owners.
Even as EU members we have not been bureaucracy free. Because the UK is outside the Schengen zone, we have been obliged in theory to show our passports on arrival, though some Schengen countries such as France often do not bother to enforce passport checks on yachts. (That might be changing, because in July, for the first time in many years, we were boarded on a mooring by French customs officers in a RIB, whose only interest was in our passports).