Not that simple !
As stated above the problems come when no base is permanent, my base can change and has. So just like the people above who want their lives run by the EU and want their pensions and state health insurance devided up and administered by four or five different EU states I shall quote part of the EU legislation pulled from the UK government site................
If a very strict application of the new rule would harm a crew member's situation because their 'Home Base'often changes, and this would mean them frequently moving between the Social Security legislation of different states, then they or their employer can apply for a special agreement to keep the person subject to the legislation of a single state.