This would result in a reduction of the signal frequency, similar to the redshift - the move towards ... possible to detect submarines hiding hundreds of metres beneath the surface.

shadowed her every move. The Yantar's crew eventually complied with a 'polite' warning issued by the submarine's crew - which included the phrase 'good morning' - and headed towards the Mediterranean.

the U-505 was one of the German navy's Type IX-class submarines, a long-range attack boat developed with longer dive times and agility compared to its predecessors. Given the Kriegsmarine's limited ...

The hunter-killer submarine was ordered to surface ... every move. “The ship then left UK waters without further loitering and sailed down to the Mediterranean.” It headed back towards the ...