A bath screen is one of the most common methods of keeping shower water inside the bath, when you have an over-bath shower fitted.
Although reasonably effective they do have a few downsides most noticeably the fact that they don’t extend far enough up the bath. This is not always a problem with gravity fed showers but power showers, can result in in spray getting out of the showering area onto the bathroom floor. Another bath screen deficiency is the fact that they are always visible, especially the curved glass type, which basically remain in place all of the time. This can make a small bathroom feel
even smaller as it cuts into the open space (even if the screen is completely clear). Even a folding bath screen (below left) takes up quite a bit of space when stowed.