Related Clues:

• Shell you may sit in
• Beach home?
• Combing find
• Turtle's 'home'
• Hard outer covering
• Carapace or cartridge
• Carapace or explosive missile
• Light rowing boat
• Shades, perhaps, of what's hard outside
• Shades of having a hard cover
• It's hard to cover the shades with this, perhaps
• Shades, perhaps, of being hard outside
• Hard to get outside such shades, perhaps
• Get ahead with this, or the sound of it (5)
• Perhaps shades of what's in the tank