Mar 4
Salt Water Spread not factoring actual sea level.
It appears to work by taking the highest point in the chunk and then using the salt content of that chunk and the relative heights of other chunks around it to determine the amount of spread. (with some decay, so mistakes are fixable to a point)
If you were to build a tall building with an overhang to the ocean, you'll start siphoning saltwater onto land. If you were to build a tall building right on the edge of the ocean, but not overhanging it, you block the saltwater entirely.
If it factored actual sea level, rather than the highest block of the ocean chunk, the unfair siphoning of saltwater would stop. Blocking would still continue, but I don't think you can fix that without a performance hit.
Pending