The grynns are old dammed barriers on military initiative. Correctly marked on nautical charts, but the straight lines with underwater rocks can be perceived as a cable or similar since it forms such an unnatural shape.
The only marking is half-collapsed signs where the paint has completely faded. Groundings are very common; I have seen about 10 or more myself over the years, including really large motorboats.
Weather
Wind
15 km/h
S(177.1°)
Swell
Height
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