Possible Clues:

• Weather phenomenon whose double lights were said to represent this puzzle's subjects
• Electrical charge that glows around a church spire, ship's mast, etc
• Electrical discharge? I feel storms brewing
• Electrical discharge on ships in a storm
• Weather phenomenon named for the patron of sailors
• Electrical glow on ships
• The luminous phenomenon that is sometimes observed round the masts of ships
• Luminous phenomenon on ships
• Electrical discharge on ships
• Corposant, electrical charge forming glow round ship's mast