Possible Clues:

• Nautical measure of six feet
• Six-foot measure
• It's just six feet down - get to the bottom of it
• Understand how to plumb the depths
• Sea depth of six feet
• Unit of six feet in measuring depth of water
• Make sense of sound
• Six feet (under the sea!)
• Begin to be overweight for the six-footer
• How a six-footer starts to be overweight