Hunters in the sea - Robin White

During the dog days of the USSR, desperate Russian scientists fought to create a weapon that could preserve the balance with the US - one that no sophisticated defence system could stop. They turned to one of the oldest killers of all - Smallpox. Modifying it to evade the human immune system, they created something so destructive that even they realised that it could never be used. The disease - codenamed HUNTER - was left to rot in an obscure lab in the heart of Russia as the Soviet state collapsed around it.
But now a disgruntled former Russian scientist has defected to a shadowy group of terrorists and has taken passage to the Middle East in a rusty freighter full of so-called freedom fighters. In his case is stored one test tube of this new plague. Out of fear and anger, he has sold his soul to the devil.

And in the midst of the worst storm in the history of the Mediterranean, only two men can stop him. Commander William Steadman of the attack boat USS Portland and Captain Rem Reonov of the Russian Akula class submarine Gepard hold the fate of the world in their hands. The trouble is their masters refuse to recognize that they're on the same side and they may have to destroy each other before capturing the ship?

But what no-one knows, least of all the hapless terrorists on the freighter, is that HUNTER is already free on the boat and that the end of the world is already upon them?