Allowing tanks to wade though shallow water was done to allow LC to unload on what would be long shallows leading to beaches.( as part of a two step process to force LC unload when they get to shallow water.....we haven't got to that stage yet as it would appear there seems to be little player enthusiasm for beach landing ) It was not intended to be used to simulate streams that have muddy banks and bottoms ( normal streams....
shallow water represents firm packed sand ). When I asked for it to be added I did not take into consideration that someone would be "creative" with it .
So now you know....if you want streams that offer normal chances of immobilization use normal streams. If you want to represent wide hard bottomed streams use single hex shallow water.
That said you CAN be immobilized in shallow water.
The " Problem" is rarely get up to speed in shallow water and speed is a big factor in generating immobilizations but also the chance of that happening is / was
intentionally reduced from streams which have a higher probability of immobilizing because the intent of allowing tanks to wade shallows onto beaches and NOT create a mass of immobilized tanks......Tarawa was a unique problem of reefs and deep water mixed in with the shallows