Related Clues:

• 'Send help'
• 'Mayday! There's a leak in our boat!'
• Boater's distress signal
• "Help!" letters
• Palindrome in English and Morse code
• Sea plea, briefly
• Boater's urgent signal
• "Get me out of here!"
• "Mayday!" letters
• Distressed dispatch
• “Help!”
• "We need help!"
• Letters spelled out with rocks on a desert island, in cartoons
• Big letters on an island beach, maybe
• Letters read from a rescue plane