Possible Clues:

• Leave still (of a ship)
• Render motionless — don't panic!
• Leave a sailing vessel unable to move for lack of wind
• Cable broadcast might, initially, take the wind out of one's sails
• 'Don't panic'
• Don't get the wind up
• Immobilize at sea, in a way
• 'Do not panic!'
• Still good advice to the overexcited
• Steady