The antenna could not be very good for AIS reception as it clearly is horizontally polarised being low and flat while AIS transmission is vertically polarised. This incorrect polarisation must give a significant signal loss on AIS. Likewise Kadeena with his presumably vertically polarised stub antenna on the pushpit for TV. It may work a lot better if it is mounted horizontally and side on to the signal source. Unless you are in area of vertically polarised TV transmission. olewill