Recently, I had a couple customer questions. The first was about anchor rode scope.  He is new to boating and anchoring.  After a long discussion, I created a PDF.  He found it useful and suggested I share it. Note that the chart has four different pages.  In the first page, the user must add the height of the bow roller from the sea level to the depth from the seabed from the sea level to obtain the “total depth” listed in the first column.  
In the subsequent pages, the “depth” is just the depth of water from sea level to seabed.  The formula for rode length includes the addition of the height of the bow roller from the sea level (6 foot or 7 foot or 8 foot).  The user only has to know the depth of the water and not do the math.”