Initially, this is an account of a rare incursion of a Japanese cargo carrying submarine, I-52, into the North Atlantic, en route to Nazi-occupied Brest in June 1944. With a little help from Enigma, it was detected and sunk with routine efficiency by an allied ASW escort group. “We got that son of a bitch” would have confirmed that the attack aircraft were from a USN carrier, even if that had not already been made clear in the narrative.

Fast forward to 1995, and the more interesting story of attempts to localise and recover the cargo of I-52 which is alleged to include several tons of gold bullion. The submarine is sitting on the bottom of the ocean at a depth of several thousand feet. Although various wartime records from the attacking force were available, the technology and navigational equipment in the 1940s were primitive by comparison with modern Satnav, and the bottom search required was not helped by the predictable unreliability of the Russian ship used by the US led research team.

This is the best part of the book and even though the wreck was found at almost the last gasp, there was no cost-effective way either of recovering the submarine or searching it for the cargo. Remote controlled vehicles (RoVs) with cameras can identify a target at almost any depth but neither recovery or internal search is possible without a massive investment of money and equipment. Neither was there any attempt to establish legal ownership of the wreck, which is still claimed by the Japanese.

Included in this easily read and well written account of the whole incident there are many interesting statistics of the numbers and types of ships that litter the ocean beds worldwide. In WW2 alone, there are 5,411 recorded under Allied and Neutral ownership, and probably as many again from their former Axis enemies.

Even when the precise position of a wreck is established there is the extreme difficulty of gaining useful access in the pressures of the deep oceans. Although the lessons in oceanography and the nature of underwater acoustics are not new, they are a useful addition to the book.