For 700 yen, you can buy a ticket that allows access (no re-entries) to the observation deck on the 7th floor, the Maritime Museum on the 3rd floor, and the Fuji Icebreaker, an Arctic Exploration ship, docked just outside the building. The observation deck is pretty basic. It's a simple room with panoramic views of the Port of Nagoya, with the best view directed toward the Sea Train Land amusement park with its big Ferris Wheel. You can see into the Aquarium from here as well and you can spot a distant glimpse of a dolphin or orca in performance (unfortunately). There are a few decent photo opportunities from up here. The museum is for the maritime enthusiasts, with a wide variety of models. Most seemed to be directed toward kids, but it could be worth a quick stroll through. I did a self-guided tour (you can rent an audio guide, I believe) which was simple enough. You can peer into the old rooms, recreated to show what life was like aboard this ship back in its 18 year span. On the deck is a Sea King helicopter which you can also get a close look into. There are 3 levels of the ship you can explore, including the Bridge. All in all, the Nagoya Port Building is an easy way to kill an hour or two for a pretty cheap price. There's not much to do in Nagoya, so you can't be too picky.

We visited the Nagoya Port building, Fuji antartic ship and the observation deck all for around Y700 per adult - good value for a 2-3 hour visit. The ship complete with supply helicopter is interesting and different, with good displays and information (mainly Japanese), but it is easy to get the idea visually. Most of the ship is accessible apart from the engine room; which can be viewed from above and the cargo hold. The port building contains the maritime museum on 3F and the observation deck on 7F. The museum is quite interesting on the whole but some of the displays lacked any information. There are also good interactive displays for the kids (and adults!) and an activity area for the more creative types. The observation deck has good views over the port and surrounding areas of Nagoya, needless to say chose your visit day to maximise the best views on a clear day. Overall well worth around half a days visit including time for a snack. If you have enough energy you may also like to visit the aquarium on the same day, but that may need an early start and turn out to be a long day.