Fine!" He called after her, "but make it 10 laps!"
Saoirse heard him as she surfaced to breathe, turning her head sideways and continued on with her stroke. The next breath she took, she had reached the wall and briefly yelled "Deal!" Before diving back into the water.
Sirius shot off too, beginning his first lap, beating his tail a bit clumsily. He had never swam that way before, or much at all, and it took him about a full lap to figure out the movement. By then Saoirse had reached the other wall and now began her second lap.
I gotta go faster! He thought a bit frantically.
He picked up speed and whipped his tail through the water. He began his second lap, crossing paths with Saoirse as she began her third lap.
Then catching up to her as she hit the wall, and he nearly passed her, but she saw him coming and picked up speed.
Swimming side by side, they shot through the water, each one trying to pass the other one.