I used 2 minutes, but you may like to go longer. Divide participants into 3 groups. Give each group a different kick board exercise. Rotate until each group has done each of the 3 exercises. Rotate the groups until each has completed each of the arm exercises.
Ski jumps Rotate the groups until each has completed of the jumping exercises.
Now go to the deep end. Bring legs back to the front again and repeat. Participants need to be strong in the shoulders to perform this exercise. Cue participants to make sure arms are vertical and NOT out to the side. These are examples of the exercises that I used, but vary to suit your own classes and add more on if time allows.