Diving Adventure / Amazon Adventure (Hal & Roger Hunt Adventures)
Author: Willard Price
Goodreads Rating: 4.24
Publisher: Random House Red Fox
Diving Adventure 1970 - Hal and Roger find sharks, jellyfish, poison, gold, and old enemy Kaggs turned religious in an underwater city near the Australia Great Barrier Reef.
Amazon Adventure 1951- Hal and Roger Hunt explore uncharted waters of the Pastaza River, deep in the Amazon jungle and collect rare zoo specimens. Threats draw their father back home. The brothers evade villainour Croc and gang, headhunters, find piranhas, pythons, jaguars. Of natives, Napo is reluctant, Aqua enthusiastic.