Deep Range (Pan science fiction)

This story takes place about 100 years in the future, when the earth's population is fed principally from the sea--on whale products or from plankton farms. Its hero is Walter Franklin, a grounded space engineer now assigned to a submarine patrol tending the whale herds.

DEEP RANGE vibrates with exciting adventures of the mysterious sea: a fight with a giant squid at 12,000 feet, a search for a great sea serpent, and a heroic rescue of a damaged submarine--all vividly and plausibly portrayed.