How to get information from Cloud shadows Dark Object Subtraction (Band Maths)

I have some data that i want to calculate the area of a lake, however, it contains cloud cover. The clouds produce shadows over the lake and when i classify the image it suggests that the shadows produced by the cloud are “bare soil”. Would Dark Object Subtraction work or is there another way i can get the data from a cloud shadow. Very new to SNAP so lamen terms would be much appreciated.