You'll kick yourself if you miss these Ocean Hall features, any one of which could become a visitor favorite.
Phoenix the Whale. The Ocean Hall's theme could be characterized as "what lies beneath." But never mind that. As soon as you step into the place, you're going to want to look straight up. That's where you'll be greeted by the hall's unofficial mascot, Phoenix. Hanging from the ceiling, she's a 45-foot replica of a North Atlantic right whale. But not just any old North Atlantic right whale. This one is a kind of portrait, a scale-model model of a living whale that has been tracked by scientists since her birth in 1987. See those rough-looking bumps on her face? They're not barnacles, but callosities (similar to the calluses we get on our hands and feet). And their distinctive pattern is what helps trackers identify Phoenix from the air. You can even touch one of those warty growths at one of the Ocean Hall's several hands-on displays.
Giant Squids. Next, head for that coffinlike metal case under Phoenix's tail. Inside? A 24-foot-long female giant squid, one of two specimens -- his 'n' hers -- preserved in a special hair-gel-like fluid developed by 3M. In a separate tank nearby you'll find a smaller, but no less eye-popping male. Now would be the time to take out your camera. The photo op -- you next to what appears to be the world's largest calamari appetizer -- is too good to pass up.
Giant Great White Shark Jaw. With a case all to itself, the Ocean Hall's one must-see fossil belongs to Carcharodon megalodon, a now-extinct giant shark whose massive size (up to 52 feet) makes that other great white from the movies look like a goldfish. The teeth here are real. Only the jawbone itself, six feet tall when poised to chomp, is a reconstruction.
Coral Reef. Clown fish and living corals abound in this stunning 1,500-gallon aquarium, designed to replicate a coral reef ecosystem. But don't just look for the star of "Finding Nemo." Check out such exotic species as the exquisite wrasse, known for its strange ability to, ahem, change sex in midlife. This is the Ocean Hall's only live display, and it's among the most beautiful.
Coelacanth. "What the hell is that thing?" a visitor was heard to mutter at a recent preview. Okay, so the coelacanth (pronounced "SEE-la-kanth") will never win any piscine beauty contest, but it has an amazing backstory. Thought to have gone extinct 65 million years ago, it was discovered alive and well in 1938, when a South African fisherman caught one. The National Museum of Natural History is the only place in the world to have not one but two preserved specimens on display: a mother and her equally pug-ugly pup.
Video Fix: Projected directly onto the walls high around the perimeter of the Ocean Hall, award-winning underwater cinematographer Feodor Pitcairn's "Ocean Odyssey" captures the diversity of marine life around the globe. Shown in a continuous loop on eight screens, the 23-minute high-def film is the visual equivalent of background music. In other words, you don't need to watch it from beginning to end. There's no sound, no narration and no plot. Dip in. Dip out. Want the director's cut? An hour-long version is available on DVD from the museum gift shop.