Joined Cases C-128/10 and C-129/10: Judgment of the Court (Eighth Chamber) of 17 March 2011 (reference for a preliminary ruling from the Simvoulio tis Epikratias (Greece)) — Navtiliaki Etairia Thasou AE (C-128/10), Amalthia I Navtiki Etairia (C-129/10) v Ipourgos Emborikis Navtilías (Reference for a preliminary ruling — Freedom to provide services — Maritime cabotage — Regulation (EEC) No 3577/92 — Articles 1 and 4 — Prior administrative authorisation for cabotage services — Review of conditions relating to the safety of ships — Maintenance of order in ports — Public service obligations — Absence of precise criteria known in advance)