Clarke joined Mike Wilson in scuba diving ventures along Australia's Great Barrier Reef and elsewhere that yielded several ocean science publications, and even underwater treasure adventures in the waters off Sri Lanka. His thrill with the underwater environment also shows in various science fiction works other than Cradle. This novel, however, very directly draws upon detailed knowledge of charter boats, scuba diving, treasure hunting, and other aquatic activities.

During much of Clarke's adult life, Great Britain, the United States, and their allies competed with the Soviet Union for political dominance in the world, and for technological superiority in military hardware and military intelligence capacity. Cradle brings Cold War politics into play as one complication the main characters face as the plot develops. The comic book buffoonery of the junior naval officers could be seen not just as a satirical twist for secondary characters, but also as...