Related Clues:

• Castaway's refuge
• Strengthen, with 'up'
• Ely, e.g.
• Capri or Wight
• Avalon, for one
• "Survivor" locale, maybe
• It's surrounded by beaches
• Emerald, for one
• Chain part
• Land and sea meeting place
• Gilligan's home
• Ocean liner?
• Maroon's locale, perhaps
• Spot on the map
• Archipelago component