Germany (Kriegsmarine). Kanonenboot K-4 Lorelei
The K-4 Lorelei was the Belgian coastguard and royal yacht Artevelde, which was under advanced construction. Captured in 1940, she was commisioned in 1943 with german weapons and sensors. Between 1943 and 1945 she escorted coastal convoys, and on October 8, 1944 sank two British MTBs. In 1945 was returned to Belgium. Served as coast guard until 1954.
The camouflage is that for a painting, but on the port side.