The marine version of the Earth-native hypothesis.
Invisible Residents proposed in 1970 that an advanced civilisation might occupy the oceans rather than visit from space. The reporting base (objects entering and leaving water) is genuinely long-standing and naval in origin, which distinguishes it from most of this branch.
Ordinary bodies and ordinary evolutionary history. Not us, but never anywhere else either.
Degree of embodiment: 5, an ordinary biological body
Scale, 1 to 5
5 is an ordinary biological body. 4 is physical but manifests oddly. 3 comes and goes. 2 is energetic or subtle. 1 is consciousness with no persistent form. Note that this tends to fall as a tradition ages.
S: speculative hypothesis
Source code
Offered explicitly as a proposal rather than a report. Rare in this field, and worth noticing when it happens.
Invisible Residents
Book, 1970
Ivan T. Sanderson's proposal that an advanced civilisation might occupy the oceans rather than visit from space, on the reasoning that water covers most of the planet and almost none of it has been surveyed.
No practice attached
Tradition-side
There is nothing to do here: no inherited method of engagement, whether the tradition is a text, an argument or a set of reports. Anyone offering you one has invented it.
Deliberate contact work
Read this first
The hazard in this subject attaches to the method, not to which name you aim it at. Ouija work, invocation, sustained channelling, induced hypnagogia, deliberate sleep deprivation and hypnotic regression are the practices associated with difficulty, and a session aimed at a benevolent civilisation is not safer than one aimed at something considered lower. What raises risk is doing it alone, doing it repeatedly, doing it while sleep-deprived, and doing it with an existing vulnerability to psychosis, mania or dissociation. People who get into trouble here overwhelmingly got there through practice, not through reading.
Who should be careful
Practice-side
Anyone with a personal or family history of psychosis, bipolar disorder or dissociative conditions, anyone in acute crisis, and anyone isolated from people who would notice a change in them. Intensive contact practice is destabilising by design (that is what it is for), and destabilisation lands hardest on people already close to an edge.