i am looking for a mooring system for a 115 ft boat that weighs 100 long tons .?

Question

i need to keep that boat five ft away from the dock and keep it from going left or right.

Answer 1

A few additional questions......are you mooring the boat perpendicular to the dock? Bow in? Stern In? Or parallel? What are the tides? Prevailing winds? Currents? All these have a tremendous effect on what you set up.....I assume you cant drive a few whacking big pilings into the bottom, so.........off the top, set at least a 100 pound Danforth or Bruce or CQR type anchor, on 3/4 inch or better chain which is at least 5 times the depth of the water long off the dock in one direction, another system in the other, and take the mooring lines from them one to the bow, one to the stern ( if parallel) or one to each side of the bow/stern if Med moored.....don't listen to people who suggest concrete blocks...you need something engineered to hold the bottom, ie a big anchor