[Irish Jigger]

Was on Franks for years. For starters you need counter weights on pulleys attached to your two bow cleats. We used cinder blocks one one each side with galvanized chain through the blocs and attached to the 1/2 inch line run thru the stainless pulleys. Do it at low tide so you know the blocks are not on the bottom or suspended in the air. Now your boat is centered in the slip. We then ran a spring line from the cleat on the dock to another pulley on each piling and put a loop in the line at your mid hull cleats.This set will pull you back from the dock/ ladder to the distance your comfortable with while the bow is attached to the counter weights. The last set of lines are in the stern cris crossing your motors from the pilings to the stern cleats. Spend a day and a full tide cycle to make adjustments. Worked for us and many others for years. Your choice of counter weights can be anything from 45 lb weight lifting plates to concrete filled 6 inch pvc with an eye hook mounted in the concrete to a simple cinderblock. I replaced the blocks every 2 years and never had an issue.Sounds complicated but is a very quick and stable way to keep your boat safe. So it's 4 stainless 3/4 inch pulleys, 2 15 foot lengths of 1/2 inch line for the stern, and a long length of good 1/2 inch line probably roughly 150 feet when all is said and done. Cutting and burning the ends with each line made.
Feel free to pm me with any questions I can help you out if needed.

Sean