[redko]

If you texture the shoreline how you want it lets say a sandy beach then go to map_c and using the smudge tool you can gently pull the colours off the beach and stain the water the same colour but diluted,
this takes a bit of practice but its another way of getting 2 water colours and then you can blur that with a water texture tile and smudge it to create a bit of depth

little question.

i'm painting map_c to indicate where shallow waters are....so the more the zone i paint is clear more shallow waters are close to surface, and more it's dark more shallow waters are deep right?