Since the release of Bedrock 1.19.0 there has been an issue with being able to see underwater while submerged. Underwater fog has increased by a factor of two or three, making it impossible to see beyond a three block radius. This effect is not helped by an active conduit. The 'conduit sight' effect that is supposed to increase vision does not continue to act on the player if they journey beyond the approximate eight block radius centered on the conduit. This is not noticeable from above the surface of the water. The conduit sight affect still works on the player if they are standing in the water, head and vision not submerged. Standing in water while within a conduit's area of effect looking out to deeper waters provides a significant clarity to what is submerged, but this goes away as soon as the player dives into the water themselves. 

This makes underwater adventuring IMPOSSIBLE and is somewhat frustrating. None of these issues were reported as gameplay changes on public forums / wiki's.