 By 1945, just five Type XXIII and one Type XXI boats were operational.The Type XXIIIs made nine patrols, sinking five ships in the first five months of 1945; only one combat patrol was carried out by a Type XXI before the war ended, making no contact with the enemy.As the Allied armies closed in on the U-boat bases in North Germany, over 200 boats were scuttled to avoid capture; those of most value attempted to flee to bases in Norway.