Possible Clues:

• Pish! Why ring the Lutine bell?
• Maritime disaster
• Perhaps it's a sea foundry that's such a dead loss
• Fate of the Titanic
• Seagoing vessel on bottom of ocean
• The end of the end of 12 across
• Calamity that may cost someone a packet!
• That'll sink at sea
• Gilligan's fate
• Why there's so much washing up?