Plot hole: When the radar man of the USS Cayuga describes a radar reading to likely be "One of the Russian cruisers", the commanding officer of the USS decides not to pursue it saying, "We are after bigger fish today - I want the Vasilyev". In the film, the Vasilyev is depicted as a destroyer, which is a smaller and lighter ship than a cruiser. In this context, the cruiser would be a "bigger fish" than the Vasilyev and the CO should pursue it instead if he was after the larger, more dangerous vessels as he seems to declare.