London: The admirals of the Soviet Union declared North Korea's prize submarine to be obsolete back in 1961, and Western experts stubbornly point out its inability to sink enemy vessels.

But Kim Jong-un, the "Supreme Leader" of North Korea, offered navigation tips and issued stern battle orders during a proud tour of a Romeo class submarine of the People's Navy.

Designed in the 1950s, the vessel was in production for the Soviet Union for only 48 months until being succeeded by nuclear-powered submarines 53 years ago. Every other navy in the world then gave up on the Romeo, with its noisy and easily detectable diesel engine - apart, that is, from North Korea's. Today, the country has 20 Romeo class boats, comprising almost a third of its submarine fleet.

During his visit, pictures of which were released on Monday, Mr Kim mounted the vessel's conning tower and went on a short voyage, during which the official news agency reported that the multi-talented leader "taught" the submarine's captain a "good method of navigation".