/**
     * Returns a friendly heading - e.g. SW
     * @param degrees The heading to convert
     */
    String getFriendlyHeadingString(int degrees){
        if ( degrees == -999 ) return "?";
        if ( degrees >= 337 || degrees < 22 ) return "N";
        if ( degrees >= 22  && degrees < 67 ) return "NE";
        if ( degrees >= 67  && degrees < 112 ) return "E";
        if ( degrees >= 112 && degrees < 157 ) return "SE";
        if ( degrees >= 157 && degrees < 202 ) return "S";
        if ( degrees >= 202 && degrees < 247 ) return "SW";
        if ( degrees >= 247 && degrees < 292 ) return "W";
        if ( degrees >= 292 && degrees < 337 ) return "NW";
        return "?"+degrees;
    }