These dolphins are milling, or swimming without any real purpose.
Milling

A clear morning with little wind.

Monique and I are on observation duty so we head off to the water tower to see if we can spot any groups of dolphins before we set up all the equipment.

We saw several small groups just milling around. Often the dolphins are milling when they seem to be in large or small groups, sometimes small sub-groups breaking away from the main group and then joining up again. They seem to change direction often, some seem to be swimming lazily, some involved in leaps and splashing. They just swim in ever changing groups, some playing, others just seem to swim to and fro without any real purpose. In a photo, you would see dolphins going in all directions with some leaping and splashing.

Then the group all moved so far across south bay that they became really difficult to track, and the wind began to freshen up so it was hard to see if the white splashes were caused by dolphins or white tops on the waves.

The boat crew saw several small groups and managed to complete four short trips before they too had to come into shore.

That afternoon even the whalewatch boats that are much bigger than our boat didn't go out.

It must be very frustrating for the research crew to have to lose so much time because the weather is too windy or the sea is too rough to get good tracking time.