This article has great graphs of vessel speed over the last months. It’s easy to see when ships are speeding up and slowing down. The speeds correlate with the spot price of shipping.
Speeding up causes more fuel to be burned, which adds to expenses. It also generates more pollution. Slowing down has been a tactic over past years to reduce pollution generated by ships.
But the long waiting time in ports these days has thrown calculations out of kilter. Now ships need to speed up to keep to their schedules.
Greg Miller, Senior Editor Sunday, November 7, 2021
After container ships sped up, why did they just tap on the brakes?
Supply Chain and Logistics 