I soo glad I found this site again!
When I am looking for a hard workout with little thought, I do the "circle workout".
After a warmup, I start the class runing in a circle (around the perimeter of the pool). Once the water is traveling with us, chage directions. When changing directions, change the jog to kicks, knee lifts, curls etc. I always do the pattern forward and backward (always working against the current). It is very hard, so I give them a "resting" step. They are in partners. One person holds the other under the arms and pulls them (with the current) on lap, then switch. The class really enjoys this work out. It lets the talkers talk to their hearts intent; if they don't hear the directions, they can see the change and catch up.