Tidal Videos

3/23/26

I recently rigged a small sail on my sea kayak and it has rejuvenated my drive for trips out on the Salish Sea. While I love the South Sound, the San Juans are undoubtedly the premiere place to be out exploring in a vessel with the plethora of islands of many types that generally have dramatic geology and scenery. 

The San Juans are notorious for their tides and as someone who is almost always solo in my kayak, I am properly intimidated by the tides. While searching for tidal internet for a trip to some islands off of Guemes, I came across the Salish Sea Tidal Atlas and the accompanying prediction chart on the internet. After one attempt at trying to use the calendar and maps to understand how the tides would be for the trip, I found it so clunky and awkward and immediately began coding up a way to make videos/.gifs of each day.

That is what I present here! I've turned the calendar that has an enumerated map for every hour in the day into a matrix that is read by my code that has processed the entire atlas into images that can be compiled in different orders based on what the 24-value vector for the day dictates.

This wasn't too tricky of a task, but I got 'er done pretty quickly whilst grinding research in the lab concurrently. There's lots of variables to tweak, but I settled on ones that semi-optimize file-size/compile time and utility. There are plenty of other resources out their with higher fidelity, but I'd argue that this version is valuable in that it is a direct reproduction of material from a skilled oceanographer using reliable data and a high resolution tidal model. I really like a UW source thats out there, but it doesn't allow visualizations very far in the future.