PURPOSE: To attain the quick and accurate application of the tide level difference in a graph by showing the tide movements within frames and columns with horizontal lines showing the tide levels and vertical lines showing the time bands respectively.

CONSTITUTION: A column W shows the tide levels and these levels are different according to regions. Then W12 is set at '0' with symbols (+) and (-) added to the W11 and W12 respectively, and numeric characters are added to each W position in response to the horizontal lines 1W13 showing the 50cm units respectively. While the numeric characters 0W23 showing times are added to columns U and V to show time point lines V0WV23 respectively. Furthermore the remarks are written into a column Y. Then the months/days of a lunar calendar, tide, full tide, hours/minutes, tide level (cm), hours/minutes, tide level (cm), age of the moon, °, edd tide, hours/minutes, tide level (cm), hours/minutes, tide level (cm), time points, tide level (cm), sun, sunrise time point, sunset time point, moonrise time point and moonset time point are written successively into frames AWT. While the port, year, month, day and day of the week are written into columns X and X1WX4 respectively.