The 1,916-passenger Oosterdam is part of Holland America Line's more contemporary Vista class. The crowd is a bit younger, though the vibe is still not party-hearty. Instead, do the New York Times crossword in the Explorations Cafe, read in a teak lounger on the promenade deck, or sip a cocktail in the piano lounge. New additions — including the gourmet burgers and hot dogs at Dive-In at the Terrace Grill — have kept the dining options fresh.