As snow fell outside, the Supreme Court on Monday spent an hour discussing cruise ships. But it was not a wistful reverie; the serious topic of the day was whether foreign-flag cruise ships must comply with the Americans with Disabilities Act because they sell tickets to U.S. passengers and dock at U.S. ports.

The justices appeared split on the issue raised in Spector v. Norwegian Cruise Line Ltd. Douglas Spector, several other people with disabilities and their companions sued the Bahamian-flag cruise operator for discrimination under the ADA after taking cruises on the company’s ships sailing from the port of Houston. They said that customers with disabilities are charged higher ticket rates and that the vessels are not configured to enable them to use facilities including bathrooms and swimming pools.