Crush depth

the long version

Reactionary enemy regimes have brutally taken command in South Africa and Germany. U.S. and European shipping lanes are suddenly under attack. World War is at hand -- and for the ruthless Berlin-Boer Axis, the devastating weapons of choice will be tactical nukes used at sea.The Voortrekker, a deep-diving state-of-the-art German submarine, is on the prowl, carrying more onboard firepower than many of the world's nations possess -- and the crippled sub USS Challenger is the only weapon in America's arsenal that can match up with the silent killer. But the nation's last hope is in dry dock -- and Captain Jeffrey Fuller, Challenger's brilliant, driven skipper, must get his damaged boat back in action weeks before it is battle-ready. Fuller has faced Voortrekker in the past and, unlike so many others, he survived. This time, however, the fight will take place in waters far too deep for a normal sub to withstand. And this time the prize will be America.