11. That sinking was also the impetus behind a renewed effort to avoid attacking neutral ships by U-boats. 12. As well as neutral ships , the warring parties had vessels at Narvik, riding anchor in the same port. 13. However, during warfare the forcible boarding of supposedly neutral ships is commonplace in the imposition of a blockade. 14. If all went to plan, the captains of the neutral ships transporting goods to France and Spain made fortunes. 15. Furthermore, the U-boats also sank neutral ships in the blockade area, either intentionally or because identification was difficult from underwater. 16. At about 21 : 30 he sighted the lights of a neutral ship on No . 8 boat's port beam. 17. Britain mined international waters to prevent any ships from entering entire sections of ocean, causing danger to even neutral ships . 18. The first part of the rule, however, makes neutral ships inviolable and so is the core of the freedom-of-navigation doctrine. 19. The French government in Versailles proposed that French goods be carried on neutral ships from the United Provinces or Spain. 20. On 12 Oct 1941 the neutral ship Corte Real was stopped for inspection by U-83 80 miles west of Lisbon.
