> The recently completed Kraft durch Freude cruise ship MV Wilhelm Gustloff was anchored in international waters near the United Kingdom to serve as a floating polling station for German and Austrian citizens living in the UK. On 10 April 1938, 1,978 voters (including 806 Austrians) were ferried from Tilbury, east of London.
I doubt that that was constitutional, but maybe it was, after all they got in power legally in 1933.