🌐EnglishEnglishDeutschFrançaisNederlandsРусскийالعربيةفارسیEntityQ2457011· pop 7· linked from 378 articlesUD-31940 O 21-class submarineAvailable in 6 languagesFrançaisالعربيةNederlandsUkrainianفارسیvia Wikidata sitelinks · CC0ConnectionsGerman invasion of the NetherlandsEntityNorwayCountryWorld War IICategories1939 shipsMaritime incidents in May 1940Maritime incidents in May 1945Naval ships of the Netherlands captured by Germany during World War IIO 21-class submarinesOperation Regenbogen (U-boat)Submarines built by Wilton-FijenoordWorld War II submarines of GermanyWorld War II submarines of the Netherlands