Blacklight

the long version

"Except for the special message from Admiralty headquarters, the British cruiser Marlin's new assignment seems routine enough to Chief Officer Webb Carrick. As part of the Fishery Protection Service, Marlin will be supervising a deep-sea fishing championship taking place off the Scottish coast, very close to off-limits submarine training waters. The Admiralty makes it crystal clear - there is a missing experimental torpedo and Carrick must take extra care to ensure that none of the competitive fishermen stray into forbidden waters. Soon Webb realizes, however, that someone is after more than just the usual catch...and then the corpse of a murdered fisherman turns up. And for Webb, the straightforward fishing championship is suddenly transformed into a sinister nautical mystery"--Publisher description.