🌐EnglishEnglishDeutschFrançaisNederlandsРусскийالعربيةفارسی日本語EntityQ2472512· pop 7· linked from 380 articlesUD-4UD-4 was a Dutch submarine and in World War II commissioned in the KriegsmarineAvailable in 7 languagesFrançaisDeutschالعربيةNederlandsUkrainianفارسیvia Wikidata sitelinks · CC0ConnectionsGerman invasion of the NetherlandsEntityWorld War IIConceptNazi GermanyCategories1940 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)Ship infoboxes without an imageSubmarines built by Rotterdamsche Droogdok MaatschappijWorld War II submarines of GermanyWorld War II submarines of the Netherlands