I didn't record a movie or compress a save before the first time I did this, so I built a replica of the first experiment's setup and ran it again for anyone interested.
This experiment shows clearly that pressure is not transmitted through tiles which have less than 7/7 water. Tiles have to have 7/7 water in order to transmit pressure.
Here's the movie, and the save file is here: http://shadowlord13.googlepages.com/firstWaterExperimentReproduced.7z
All you have to do is let it run. It will start as soon as that one tile is changed into stairs down.
No comments have been added to this movie.
Pineoaks