No predictions loaded for 1993. This site serves NOAA predictions from its own store, and this period has not been fetched for Spee-Bi-Dah 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/wa/spee-bi-dah-9448009/1993
Spee-Bi-Dah, WA tide table 1993 (printable) · Tide Almanac