Possible Clues:

• Soothe
• Don't panic - it's one of the problems trying to move the boat
• Make still or quiet
• "Chill out!"
• "Don't panic!"
• "Don't panic"
• Still good advice to the over-excited
• "Chill out!" (2 words)
• Leave (sailing ship) unable to move
• Keep motionless by lack of wind