In the 1967 movie "The Graduate," a family friend condensed his career advice to young Benjamin Braddock to one whispered word: "Plastics."
How times have changed.
Fifty years later, cruise lines are taking steps to reduce the amount of plastic at sea. Their target specifically is single-use plastics: disposable items such as coffee stirrers, water bottles and straws.
"By 2020, our target is to eliminate all consumable plastics from the entire fleet, not only for Royal Caribbean International but for Royal Caribbean Cruises Ltd.," Michael Bayley, president of Royal, said on a recent cruise.
As a down payment on the goal, Royal decided to make its newest and largest ship, the Symphony of the Seas, essentially free of plastic straws. But it wasn't easy. Substituting paper for plastic more than doubled the price, and getting them wasn't easy.
"We couldn't find a provider to give us enough paper straws," Bayley said.
So why the fuss?
Cruise lines are fighting to be seen as good stewards of the environment, and one of the many issues activists have raised with cruise lines and other hospitality companies is the high cost to the environment of throw-away plastic.
Americans toss as many as 500 million plastic straws a day. Most of those are made from polypropylene and wind up in landfills, where they take decades to biodegrade. Some also end up in the water, eventually littering beaches, choking sea birds and animals and breaking up into tiny bits at sea.
As companies that do business on the ocean, cruise lines are especially sensitive to charges of plastic pollution. So several cruise lines have recently said they are taking action to cut down on drinking straws.
Last month, Carnival Cruise Line brand ambassador John Heald announced on his Facebook feed that Carnival passengers would no longer be offered a straw but would have to ask for one.
Norwegian Cruise Line and Royal Caribbean have adopted the same policy. On a Royal cruise on the Independence of the Seas earlier this month, signs were posted at the bar telling patrons to ask for a straw if they need one.
Critics have derided the industry as slow to act, but Bayley said closing the plastic spigot is more complicated than it might seem.
"You can't just switch something off and expect supply chain manufacturers to accommodate a new version," Bayley said. "For example, when we decided to switch off plastic straws on Symphony, we could not find enough suppliers to provide paper straws."
Even when adequate supply for one ship was secured, a licensed vendor, Starbucks, couldn't go from plastic to paper. "Their global machine couldn't suddenly switch it off," Bayley said.
Stephanie Cardelle, a spokeswoman for Norwegian, said it ran into the same problem with Starbucks on the Norwegian Bliss.
Both cruise lines said Starbucks is working on a solution.
And then there's the milkshake dilemma.
When Royal tried substituting waxed paper straws for plastic ones for the milkshakes at Johnny Rockets on the Symphony of the Seas, the straws collapsed.
"These are very real issues," Bayley said, somewhat tongue-in-cheek. "It was a balance between a good milkshake and the environment, and the good milkshake won. If you have ever tried to serve a milkshake to a bunch of kids with a straw that doesn't work, it's not a pleasant experience."
Bayley said Royal Caribbean has formed a plastics team in Miami to sort through ways of eliminating plastics over the next few years. Bayley said the biggest challenge will be plastic water bottles.
"What do we do about that?" Bayley said. "We're trying to figure it out."