NEW YORK-SpongeBob SquarePants is crossing over from TV to hotels. On Thursday, Marriott International announced from the Marriott Marquis in Manhattan an agreement with Nickelodeon and Miller Global Properties to develop a new brand of hotel, Nickelodeon Resorts by Marriott. The group expects 20 properties to be under construction by 2020, with the first, a 650-room resort, breaking ground next January at Liberty Station in San Diego. "This is an unbeatable combination," said J.W. Marriott, Jr., chairman and CEO of Marriott International, who at the end of the press conference was doused with a nice helping of Nickelodeon's trademark green slime. Of course, a partnership between Marriott and Nickelodeon means that the resorts will be family oriented. The centerpiece of the new properties will be expansive water parks with climbing structures, dunk tanks and slides. Nickelodeon already has such a property in Orlando under a franchise agreement with Holiday Inn. Rooms at the resorts will be oversized to accommodate families of four or more. Richard Hoffman, executive vice president of mergers and acquisitions for Marriott, said that room rates may be higher than some resorts, but the value will be better because families won't have to book more than one room. Other fixtures will include full-service restaurants, spa services and the ubiquitous presence of Nickelodeon characters on the grounds. Marriott said the properties will fill an important segment of the leisure marketplace and stressed that while the properties will be kid friendly, they, too, will feature many components for adults. Marriott and Nickelodeon expect to grow the brand internationally, even in colder areas where indoor water parks will be built.