I used an eye bolt in a large Folgers plastic coffee can and filled it with concrete for my anchors. Using a 100' line, I loop the very back end to the aft cleat with a loop and a clamp at 21'. It hangs straight down at the stern at 17'. At the other end of the line (79') I have another loop with a brass clip.
I wrap the entire line onto an orange spool designed to hold a 100' drop cord. After the hook is tied in to the dive site, I deploy the system by attaching one of my coffee can weights with the clip on the bitter end. I then attach that to the main anchor line with a large SS carabeener and drop it in the water. It slides down the anchor line to a depth of about 40'. I then attach the 2nd weight to the clip at 21' feet, drop it in and walk to the stern to attach the end to the stern cleat. What this gives me is a line straight down to about 15' and then a guide line that gradually descends to a point at the main anchor line at 40' deep.
One note. Concrete is pourous. These weights are 13# on the boat, but are just heavy enough to hold the line down, but never a positive diver. I had someone tell me that they were not heavy enough and he couldn't hold himself down with the line for his safety stop. Now I include in my briefing that it is the divers responsibility to be slightly negative at the end of their dive so they have no issues maintaining a depth of 15'. But I also made a new weight by drilling a hole in two 5# weights and threading them onto the eye bolt before filling up the coffee can with concrete. It weighs 21 pounds on the boat. I like the coffee can weights because they are soft and stable on the boat deck.
I also can do the anchor line and carolina rig deployment from amidships near the helm, but that is another system.
