The URL should probably be something like:
http://localhost/boatsforsalenow_mysqli/categories/details.php?RecNo=11791
Then on the details page this line:
$rsCanalBoatDetails->bindParam("i", "".($rsCanalBoatDetails->getColumnVal("RecNo")) ."", "-1"); //WAQB_Param1
should probably be:
$rsCanalBoatDetails->bindParam("i", "".($_GET("RecNo")) ."", "-1"); //WAQB_Param1
You can't refer to a recordset value in a parameter for the recordset that you are creating. I think you want to use the passed in value from the url instead.