I did a bit of update work on the scripts I developed last year. One of those takes a series of tide times and heights, as found in your average tide timetable and interpolates what happens every hour between those. So using the rule of twelfths I can calculate the tide height and therefore the speed of tidal flow at any point between high and low water.
However last year I built the code rather specifically for the tide table I had at that point, so the code required some modification and generalisation from last year. The result does produce a pretty graph however:
(red dots are the given high and low water heights/times, blue line is my interpolations between them)
The other code I modified is the script that chooses the sites to visit the next day. This required some modifying to work for the lower number of sites on St. Agnes. This alas, does not produce pretty graphs.