Aquatic or transmedium non-human intelligence refers to proposed intelligences associated with Earth's oceans, lakes, and other bodies of water — including Unidentified Submerged Objects (USOs), entities reported entering or exiting water bodies, and non-biological underwater intelligences. This category explicitly excludes cryptozoological animals (sea monsters, lake creatures) and focuses on intelligences displaying the same anomalous performance characteristics as UAPs: extreme manoeuvre, apparent intelligence, transmedium transition (water to air and air to water) without observable propulsion or disruption.
USO reports — structured craft or luminous objects moving underwater at extraordinary speeds or transitioning between water and air — predate the modern UAP era. Eighteenth and nineteenth-century maritime logs document glowing underwater phenomena observed by multiple crew members that defy identification as bioluminescence or natural phenomena. Systematisation of USO reports began with researcher Ivan T. Sanderson, whose Invisible Residents (1970) presented the first comparative analysis of underwater anomalous reports and proposed that Earth's oceans might harbour an advanced non-human intelligence predating human civilisation.
Sanderson's analysis noted that approximately 50% of all UFO sightings in the modern era occur near or over water (a figure supported by later statistical analyses of MUFON and NICAP databases), and that a significant subset involves objects entering or exiting water without the turbulence or sonic effects expected from physical craft moving at high speed through a fluid medium.
Following the dissolution of the Soviet Union, a body of classified Soviet Navy intelligence concerning anomalous submarine and underwater phenomena was partially released to researchers. Paul Stonehill and Philip Mantle, in Russia's USO Secrets (2010), documented cases from declassified Soviet Navy archives including:
The authenticity and chain of custody of these materials varies; Stonehill and Mantle accessed materials through both official channels and researchers with direct access to Soviet-era military archives. Soviet military UFO/USO research was conducted by a classified programme analogous to Project Blue Book, apparently more extensive and better resourced.
The waters around Puerto Rico and the Puerto Rico Trench — the deepest point in the Atlantic Ocean at approximately 8,400 metres — have produced an anomalously dense concentration of USO and transmedium UAP reports since the 1960s. Researcher and journalist Jorge Martín, who has investigated Puerto Rican anomalous phenomena for several decades, documented hundreds of cases involving objects entering the ocean near the trench and returning to the air, as well as encounters by Puerto Rican Coast Guard and Navy personnel.
A widely documented Puerto Rican case involves U.S. military personnel at Roosevelt Roads Naval Station observing an object approximately 100 metres in diameter entering the ocean at high speed during a 1988 military exercise, followed by an emergency response and the subsequent closure of the area to civilian vessels. The incident is documented in interviews with military personnel conducted by Martín and later confirmed by a former Roosevelt Roads officer in interviews with MUFON investigators.
The geographical concentration of incidents near the Puerto Rico Trench — whose depth and remoteness would provide maximal concealment for underwater operations — has led some researchers to propose a permanent underwater installation in the area. No physical evidence of such an installation has been independently verified.
A set of photographs attributed to the nuclear submarine USS Trepang (SSN-674), reportedly taken during a classified exercise in the Arctic in March 1971, surfaced in French UFO magazine Top Secret in 2015 and circulated widely thereafter. The photographs show various structured objects — some disc-shaped, some cylindrical, some appearing to transition between water and air — against Arctic ice and sky backgrounds.
The photographs' provenance is disputed: they were provided to the magazine by an anonymous source claiming they originated from the National Archives through a Freedom of Information request. The USS Trepang was indeed operational in the Arctic during the period in question; the Navy's response to media queries about the photographs was neither confirmation nor denial. Some researchers consider the photographs genuine classified documentary evidence; others argue they show ice formations, experimental Navy equipment, or hoaxed images. No definitive analysis has been possible from publicly available copies.
The 2020–2023 Congressional UAP disclosure process explicitly recognised the transmedium capability of UAPs. The NDAA 2023 definition of UAPs includes objects operating in space, air, or water environments — the first time the U.S. government formally acknowledged that the phenomenon is not limited to aerial observations. Former UAP programme official Luis Elizondo confirmed in multiple media interviews (2017–2023) that classified reporting included numerous transmedium cases, including objects entering and exiting the ocean at speed without generating expected wake signatures or detectable propulsion.
Ryan Graves, in his 2023 Congressional testimony, referenced encounters by Navy aviators off the Atlantic coast involving spherical UAPs operating at the ocean surface — consistent with the transmedium category — and noted that the frequency of such encounters was systematically unreported due to career concerns about stigma.
The amphibious civilizational teachers of Dogon cosmology, associated with the Sirius star system and paralleled across Babylonian (Oannes), Sumerian (Apkallu), and Egyptian traditions. Their tradition encodes astronomical knowledge — including Sirius B's 50-year elliptical orbit — apparently inconsistent with naked-eye observation.
The most frequently reported aquatic NHI type — humanoid in body plan with pronounced aquatic adaptations: gill structures, webbing, smooth moist integument, and wide-aperture eyes. Appearing near rivers, lakes, and coastlines across independent global traditions and modern encounter accounts.
Beings presenting a cetacean morphology — dolphin or whale body plan — at anomalous scale, with coloration or capabilities beyond known biology. Connected in contact literature to Sirian intelligence and a proposed seeding of cetacean consciousness in Earth's oceans. Associated with acoustic consciousness technology.
The most morphologically radical aquatic NHI type — multi-appendaged, radially or irregularly symmetric, bioluminescent, and associated with deep-water environments. Lacking humanoid facial features; described as conveying extreme antiquity and a diffuse, vast cognitive presence unlike individual NHI types.
This page presents documented research and reported phenomena. No claims about validity or mechanism are made by this archive.