I generally avoid LOZ, reasons are obvious. Have done some dock shooting there. Looks like shooting under or around the boats is not the problem. Jigs on the dock surface are, you say.
All I know who dock shoot are responsible enough to retrieve any errant jigs on a dock surface. Unfortunately, there are dinks out there. All sorts.
Perhaps something to stop jigs around and above the dock edge that is removable so you can swim or whatever might work. The orange netting used at construction sites comes to mind, I am sure there are other options.
Might keep a non-swimmer kid from going in also. Good luck with your issue.