This is just a notice... so maybe you had notices turned off in your php.ini and it doesn't effect the functionality of the page. You could just turn off notices.
The error implies that the page needs a RecNo passed in the url in order to work properly and none is present.
To account for when no RecNo exists you can update line 14 from:
$WADAboats_details->bindParam("i", "".($_GET['RecNo']) ."", "-1"); //ParamRecNo
to:
$WADAboats_details->bindParam("i", "".(isset($_GET['RecNo'])?$_GET['RecNo']:"") ."", "-1"); //ParamRecNo
Did this help? Tips are appreciated...
