What is to herring as school whales?

This is a bit of a tricky question, playing on the common phrase "school of fish". There isn't a direct equivalent for whales. Here's why:

* Schools are for fish: "School" specifically refers to a large group of fish swimming together in a coordinated way.

* Whales have pods: Whales, being mammals, don't form schools. They typically form groups called pods, which are usually smaller and have a more social function.

So, the answer is: There's no direct equivalent to "school of fish" for whales. You could say "pod of whales" instead.