The pipes need to be driven into the soil or sand on the sides of the dock at the shallow end of the dock. I had a very rocky lake bottom and had to try several locations to find the right ones. I used a hand held sledge hammer to drive them until the tops were just below the top of the deck. . Get the caps. I did not purchase the botttom points which may make the job easier. You will need to purchase galvanized or stainless bolts, washers and nuts to attach the brackets to the deck. You can also use lag bolts if your application won't allow bolts. If your deck rises and falls with the tide or height of the water, tighten the bolts so that they allow the brackets to raise and lower with the dock while the pipes remain fixed. I used one set of two and put one on each side of the dock which seems sufficient for an inland lake in PA.. If this is a larger lake or bay or ocean application, i would get longer than 6 feet for the second set of pipes.
We do not have specific product knowledge of the that model auger.
1.66 refers to the outside diameter.
The pipe diameter is 1.66 in..