During a quick swim at lunchtime, I came across two yelloweye leatherjackets - Pervagor alternans - that were courting.
How special to see this. Normally shy and a little timid, these little leatherjackets were quite happy concentrating on each other as I watched. They would come together, side by side, then turn and face the other way. This motion repeated over a period of about five minutes as I watched. It was all highly choreographed and fascinating to witness.
Below is the sequence of events from top left to bottom right.