When beaching his boat in certain locations, a friend needs to put out a stern anchor to keep from swinging (so more boats can beach along the spit). We found lots of information about anchoring, even calculations for two bow anchors, but nothing at all about stern anchors. Did we find nothing because stern anchoring is discouraged? I told him to use the same size he has on the bow. Its a 26'Glacier Bay and the location has a sandy bottom.