INT 1 · I 25
Unsurveyed or inadequately surveyed area
Depths & contoursCore
A warning legend and broken limit mean the depth information is incomplete or unreliable.
What it means
A broken limit with an 'Unsurveyed', 'Inadequately surveyed', or similar warning identifies water where sparse or old data may not reveal every danger.
Why it matters
Blank water is not evidence of deep water. Allow a much larger safety margin and avoid shortcutting through the area without reliable local information.