Carnival Cruises has said it will maintain its policy of using drug detection dogs to find cannabis and other drugs aboard its ships. Federal law overrides state law for all major cruise lines operating or departing from US ports, and cannabis is prohibited in most circumstances despite the ships not being flagged in the US. The use of dogs has caused some concern among passengers with allergies, but a cruise line spokesman said the ships were large enough for this not to be an issue. Royal Caribbean, Norwegian Cruise Line and other major operators have similar zero tolerance policies and maintain drug-free zones throughout their ships.
