Unidentified Submerged Objects have long existed on the margins of UAP/UFO research, mentioned in passing and rarely examined in depth. Yet the historical record tells a different story. Reports of anomalous craft operating within Earth’s oceans, lakes, and rivers are widespread, persistent, and often difficult to dismiss.

In this second volume of A History of USOs, historian Richard Dolan presents a detailed investigation of global cases from 1970 to 1989, a period marked by a rise in both the frequency and intensity of encounters. Drawing from military reports, civilian testimony, and archival research, the book assembles evidence spanning continents and political systems, including repeated interactions involving both U. S. and Soviet naval forces.

The events themselves are often striking. Large objects move beneath the surface without detectable propulsion. Craft emerge from the water and ascend into the air with controlled acceleration. Close encounters occur near shorelines, in open ocean, and in inland waterways, sometimes accompanied by equipment disruption, physiological effects, or gaps in perceived time. Many involve trained observers in environments where misidentification carries consequences.

The pattern is global and persistent. It appears across decades, cultures, and very different observational contexts. During the Cold War, increased human presence in the oceans, along with advances in sonar and submarine technology, brought more of these encounters into view. Even so, the capabilities described remain outside any publicly acknowledged technological framework.

This volume places these encounters within their historical setting while examining the implications of a sustained, largely unacknowledged presence in the world’s waters.

The oceans cover most of this planet. Large portions remain unexplored. Whatever operates within them has had ample space to remain out of sight.