John D. Alden, retired Navy Commander (according to William Tuohy in "The Bravest Man") updated the JANAC figures in the 80's/90's after he had learned that the Japanese figures had been updated with more accurate data than was available to JANAC. According to Tuohy, Alden's figures are probably the most accurate. Great book by the way! Tuohy tells a great story about O'Kane and some of the more colorful Sub Skippers of that time.
