I make one with 1/2 " heavy conduit. Thread coupling on one end...then 7/8 or 3/4'....can't remember.. steel bolt in coupling...with head cut off bolt. Sharpen head on grinder. Put threaded Tee on top for rope. This set up is not to heavy, but a good hard hit or 2 and I'm good to walk on it. In Indiana we are just looking for 2 1/2" or more...to start fishing on....in the shallows.
Don't use it to make holes to fish in.