Monday, 2 September 2013

Tides

For people who use watercraft in the ocean, tides are important. They influence where you can go and how hard it will be to get to your destination. 

In Vancouver, you can get official tide predictions in the form of tables.
ernment tide table

A web program called Tides can also show unofficial predictions in the form of a graph.

Unofficial tide chart from Tides program

Notice that the graph is much faster to interpret. Unfortunately, because the data is unofficial, you can't really rely on it if you need really accurate tide predictions. I think the ideal would be the official predictions in graph and table format.

The other problem I see with the government presentation of the data is that the exact location of the prediction is not shown with a map. I suppose you could look up the location on another chart, but this is more work and takes more time. Tides can vary depending on the exact location, and Vancouver has a very large coast with major land barriers that influence the actions of the ocean level. 

Good design for accessibility usually results in better usability for all. Do you see any other concerns with the tide data?