A chokepoint chart is only meaningful against its own history. Absolute transit counts differ by an order of magnitude between Malacca and Panama, and both have strong seasonal shape, so the number that matters is not how many ships passed today but how that compares with what this day of the year normally looks like.

The shaded band is the daily minimum and maximum over the previous five complete years. A line inside the band is an ordinary day. A line that leaves it — and stays out — is the thing to write about.

Read the panels together rather than separately: traffic diverted from one chokepoint has to appear somewhere else, and the Cape of Good Hope is where Suez and Bab el-Mandeb traffic goes when the Red Sea stops being attractive.