EuroGraphics Submarines & U-Boats 1000-Piece Puzzle. The underwater world, ever fascinating and dangerous. Learn about these fantastic engines that are submarines like USS Virginia, USS Typhoon, U-99 and K-141 Kursk. More than 20 submarines are illustrated on this puzzle. Strong high-quality puzzle pieces. Made from recycled board and printed with vegetable based ink. This superior quality puzzle will delight and educate all at the same time.