Possible Clues:

• Indication of a good beach - no danger in sight
• "It's safe to come out"
• 'It's safe to come out'
• "You can come out now"
• With good visibility in seaside resorts, there's no apparent danger
• 'It looks safe!'
• 'We can go safely now'
• No risk now the sea-fret has lifted?
• With the Lyme Bay spillage cleaned up, there's no danger
• Aesthetic carols performed, though no one's about