The site for the coast guard has that statement, but it didn't have the sentence about passengers not required to attend???? I copied it and will paste it below, there is a link to the site on the know before you go board and I copied the following from that site:............
Emergency Drills. Coast Guard regulations and SOLAS require that the master of an ocean cruise ship periodically hold fire and lifeboat drills. They are intended not only to give the crew practice, but also to show the passengers how to act in the event of an emergency at sea. Passengers should participate fully in these drills. The timing and frequency of the drills depends in large part on the length of the voyage. On voyages that will last more than one week, the first drill will be held before the ship gets underway (passengers who embark at the last minute sometimes miss this drill), with additional drills at least once a week thereafter. On voyages of one week or less, the drills must be held within 24 hours after leaving port.
Coast Guard and international regulations also require a notice to be posted conspicuously in each passenger cabin or stateroom. The notice explains the following: How to recognize the ship's emergency signals (alarm bells and whistle signals are normally supplemented by announcements made over the ship's public address system); the location of life preservers provided for passengers in that stateroom (special life preservers for children will be provided, if necessary, by the room steward); instructions and pictures explaining how to put on the life preserver; and the lifeboat to which passengers in that stateroom are assigned. (Note: Passengers need not be alarmed if they discover that the total number of person's on board a cruise ship (passengers + crew) exceeds the total capacity of the ship's lifeboats. Modern cruise ships carry a variety of survival craft. Passengers are invariably assigned to lifeboats or similar survival craft. The total capacity of all the survival craft on board will exceed the total number of persons on the vessel).
When fire and lifeboat drills are held, crew members from the stewards department are generally responsible for assisting and directing passengers in the drill. Direction signs showing the path to reach lifeboats are posted in passageways and stairways throughout the ship. The crewmember in charge of each lifeboat will muster the passengers assigned to that lifeboat, and give passengers any final instructions necessary in the proper method of donning and adjusting their life preservers. If there is any portion of the emergency procedures the passenger doesn't understand, they should question the crew until the instructions are clear and completely understood
