The narrows keep the lower basin connected to the wider ocean and complete Lumael's north-to-south hydrology.
The watershed's southern edge
Water leaving Lumael Cove passes through the narrows to the ocean. The exchange can carry ocean mist, salinity, heat, and life back into the sheltered lagoon.
These tides arise from Veyra's oceanic and solar systems. The Absent Moon has no measurable mass and contributes no lunar tide.
A threshold in both directions
The narrows carry the watershed outward, but they also let the wider ocean enter Lumael through salt, organisms, temperature, current, and weather. Cove ecologies therefore live with exchange rather than behind a sealed freshwater boundary.
That relationship is a concrete example of Veyran reciprocity before any civic principle is explained: the lower basin remains itself because it is connected, not because it has been isolated from change.
Why the outlet matters
The north-to-south flow is directly observable and preserved in the regional account. Exact local currents and every ocean-facing habitat have not yet been authored, but the outlet itself is not optional geography. Lumael is a sheltered lagoon and watershed, never a closed caldera.
For the visitor, the narrows keep the opening map from feeling like the whole world. Every southbound current points beyond the cove toward Veyra's ocean-rich regions and future journeys the Atlas has not yet named.