Is the Ocean Samadhi a metaphor or an actual meditation?

Question

In Huayen related documents I see the phrase "ocean samadhi" a lot. (also ocean mirror samadhi, ocea seal samadhi) Here is one source:

Huayan teaching features a range of holographic samadhi instructions drawn from the Flower Ornament Sutra. These practices help clear away limited preconceptions, foster fresh perspectives on reality, and expand mental capacities by expressing our deep interconnectedness.

... Another model is the "ocean mirror" or "ocean seal" samadhi. In this image, awareness is like the vast ocean surface, reflecting and confirming in detail all phenomena of the entire universe. Waves of phenomena may arise on the surface of the ocean, distorting its ability to mirror plainly. But when the waves subside as the water calms and clears, the ocean mirror again reflects all clearly. Our individual minds are like this, often disturbed by turbulence, but also capable of settling serenely to reflect clear awareness.

Ref.

I searched Cleary's Avatamasaka translation and only found the word Ocean used as a metaphor or simile. (The kindle stops searching at 500 hits, well before the end of the book)

Anyhow, can't tell if this is a sort of visualization exercise, literally involving thinking about waves and the ocean, or if this is just a metaphor for the meditative states achieved in samyak-sam-bodhi.

Answer 1

The waves and the ocean metaphor are found in several places in the Lankavatara Sutra where the storehouse consciousness is said to be like the ocean and the waves are like the other seven consciousnesses, so I think the term Ocean Samadhi most likely refers to the state in which the other seven consciousnesses cease.

Answer 2

Sounds like Mahamudra , (Maybe? Let me know if I am off base here)

Mahamudra cannot be taught. But most intelligent Naropa, Since you have undergone rigorous austerity, With forbearance in suffering and with devotion to your Guru, Blessed One, take this secret instruction to heart.

Is space anywhere supported? Upon what does it rest? Like space, Mahamudra is dependant upon nothing; Relax and settle in the continuum of unalloyed purity, And, your bonds loosening, release is certain.

Gazing intently into the empty sky, vision ceases; Likewise, when mind gazes into mind itself, The train of discursive and conceptual thought ends And supreme enlightenment is gained.

Like the morning mist that dissolves into thin air, Going nowhere but ceasing to be, Waves of conceptualization, all the mind's creation, dissolve, When you behold your mind's true nature.

Pure space has neither colour nor shape And it cannot be stained either black or white; So also, mind's essence is beyond both colour and shape And it cannot be sullied by black or white deeds.

The darkness of a thousand aeons is powerless To dim the crystal clarity of the sun's heart; And likewise, aeons of samsara have no power To veil the clear light of the mind's essence.

Although space has been designated "empty", In reality it is inexpressible; Although the nature of mind is called "clear light", Its every ascription is baseless verbal fiction.

The mind's original nature is like space; It pervades and embraces all things under the sun. Be still and stay relaxed in genuine ease, Be quiet and let sound reverberate as an echo, Keep your mind silent and watch the ending of all worlds.

From Tilopa's Mahamudra Instruction to Naropa in Twenty Eight Verses