LOTHAR-GUENTHER BUCHHEIM, the author of German war novel Das Boot died of heart failure on Thursday (22FEB07) at the age of 89. Buchheim's most famous work detailed the life on World War II Nazi submarine U-Boot - the writer drawing on his own experiences as an officer on submarines, destroyers and mine-sweepers during the war. The book was turned into an epic six-hour film by Wolfgang Petersen in 1981 - ten years after it was first published.