I had to think about this and wanted to pose the question to others as well. Are you one who thinks about your stroke — one at a time, in the moment I’m taking it, until I’m finished — while doing a swim? I guess that's what I've been doing lately as 1) I'm usually swimming at the same time as my son's swim team and hear and see what is being taught to them, 2) I'm trying to get faster and more efficient.

My stroke thoughts are primary, conscious and explicit. Anything else that passes through my consciousness is momentary and mostly implicit. Even my observations of other swimmers leads back to thoughts of my stroke – either to mirror or emulate something they’re doing well, or to strive for even greater efficiency, ease, relaxation or sense of leisure when I see examples of the opposite in their strokes. The later being very common now as all the New Year's Resolution crowd is back in full swing.
But I would have to think others are, in no certain order:
Think about work or school.
Think about friends or family.
Think about nothing (zone out).
This is the essence of mindfulness in all swimming, but particularly in open water. I do not fare as well in open water as in the pool, but I am improving. Does your thought process change when in open water versus the pool?
In open water, stroke thoughts are the foundation for creating a “cocoon of calm” that helps those less comfy without having a lane marker below you– especially the new triathlete – keep anxiety or stress at manageable levels. Eventually this sense of calm control should convert into flow states and pure pleasure in environments that cause anxiety or distraction in others. Seeing a shark fin can elicit the same anxiety as a poor stroke as well.
What about you? What do you think about in the water?