Orejas de ellos, the things who listen

Whispered the superstitious fishermen when the strange occurrences began off the Philippine coast. How else could you explain the sudden disappearance of a vessel beneath a mysterious curtain of foam? The writhings of thousands of maddened fish trapped in a coffin-like area of ocean? An alien intelligence gorged at the bottom of the Luzon Deep and made its plans.

Radar expert Terry Holt and the crew of the Experance had to devise a weapon against the horrifying creatures which threatened mankind with extinction. Here are terror, excitement, and the clutch of cold death as combined by a master hand in the field of science-fiction. (Goodreads)