I strongly recommend a swim brief for water aerobics as this will provide you with more freedom and flexibility. If you are feeling shy, try a fuller-cut brief or a square leg suit. Once you are feeling more comfortable, try a European cut like the Speedo Solar 1″ brief. This will offer you more movement and proper coverage. I tend to rotate back and forth between these and other styles. I understand women wear full-cut conservative one-piece swimsuits, so your swim brief will be the perfect companion.