How wonderful, in me the infinite ocean, the ship of the universe wanders about, driven by the wind of its own nature, and yet I am not disturbed
Adding a ship driven by "the wind of its own nature" introduces a specific causal claim: nothing beyond the self is needed to explain the universe's behavior.
This verse adds two elements not present in the closely related images around it: the universe is pictured as a ship rather than a wave, something that wanders rather than merely rising and falling, and its motion is attributed to "the wind of its own nature" (svabhava) rather than to any external or divine agency. Ascribing the ship's wandering to its own nature keeps the Gita's account of causality consistent with its non-dual claim, since nothing beyond the self is invoked to explain the universe's behavior — even the wind driving the ship is, like the ship, ultimately just the ocean in another form. The closing claim, "I am not disturbed," is the verse's real point: an ocean, however much traffic crosses its surface, is not altered by that traffic, and Janaka reports his own being in exactly these terms. Read with the other chapter 4 exclamations, this verse supplies the emotional key to the whole cluster, detachment not as effortful restraint but as the simple fact that an ocean has nothing to be disturbed by.
How wonderful! In me, the shoreless ocean, the ship of the universe wanders about, driven by the wind of its own nature. I am not disturbed.
Ashtavakra Gita