That area had (software generated?) coastline, that was propably based on low waterlever image.  As it had  very short lines.  In magnitude of meters.  And features which are when mean sea level under water surface.   I modified coastline to correspond the mean sea level coastline and increased distance between line points to more sensible (for me)  10 to 20 meters.  Based on same MML backround as pevious.

Aki