user: Question: Which Nation has the USA-18 sail?
Columns: ['Sail', 'Yacht', 'Syndicate', 'Yacht Club', 'Nation']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['USA-9', 'Jayhawk', 'America 3 Foundation', 'San Diego Yacht Club', 'United States']
SQL:

assistant: SELECT "Nation" FROM "Table" WHERE "Sail" = 'USA-18';