Possible Clues:

• During exercises, have a breather and a swim
• Sudden dip
• Have a breather in gym or else swim
• What some necklines do
• A dive making small change to charge
• 'Dive, plummet (6)'
• 27 down starts to take this
• Quickly dive
• Parking with breathing space east of small pool
• Dive with breathing apparatus during exercise