Navaleye - a most interesting observation about under-the-keel torpedoes. Given that the US and Germany had torpedoes intended for UTK fuzing in WW2, which were unreliable, and the RN used the Mk8 in the Falklands because the Tigerfish was not ready/reliable, and reliable UTK came in with the later TF, MK48 ADCAP and Spearfish... that has to be one of the longest pursuits of a specific weapon capability on record.