Water aerobics is back at the North Lake Natatorium, 5001 N. MacArthur Blvd. Classes are held from 7 to 8 p.m. on Tuesday and Thursday. Water aerobics is a workout that can be modified to your fitness level and a great way to have fun. The cost is $35 per month, $90 per quarter or $5 for drop-ins. Register in person with an instructor prior to class or online at SoggyZoggy.com.