No predictions loaded for 2006. This site serves NOAA predictions from its own store, and this period has not been fetched for Castle Hill yet. Nothing is estimated or interpolated in its place. NOAA's own page for the station has the official table: tidesandcurrents.noaa.gov.
tidealmanac.site/us/ri/castle-hill-8453201/2006
Castle Hill, RI tide table 2006 (printable) · Tide Almanac