Every gauge we read

Each one links to its own evidence page: level, movement, publisher classification, same-date history, and the authority's own forecast.

The corridor type matters more than the number. On a free-flowing stretch the level is the constraint. On a lock-held stretch it is not — the gauge is there for the high-water side. A Waterlogged clear-line is our own arithmetic: the gauge reading at which the published reference depth, minus the ship's draught and a fixed safety allowance, still leaves a comfortable margin. It is not an operator's decision rule and no cruise line uses it.

All gauges

Where each of these comes from, and under what licence · the threshold diary · feed health.