Jane S.
Yelp
My cheap-ass parents have been taking me to the Hatfield Marine Science Center multiple times per summer since I was a little kid. For an aquarium that is roughly twelve dollars cheaper than its neighbor to the south - or exactly $14.95 cheaper if you keep your head down and run past the "suggested donations" lady - the Hatfield isn't too bad. The big ol' octopus is always fun to watch, even if they don't let visitors stick their arms in the tank anymore. The touch pool has a child-pleasing array of anemones, rockfish and skates. Everybody likes the chaos wheel and the whale-song exhibit, and while the collection of actual live exhibits is sparse, it's always fun to watch the fish do their thing.
Yet the tourist appeal of the Hatfield is limited by its low funding and advanced academic purpose, and those who do not consider themselves amateur marine biologists may find themselves without much to do. Exhibits do not change often, and what is there can be very dry. Clunky exhibits on pinworm infestation and different types of silt are about as child-friendly as is humanly possible, which is to say that most kids who are not into biology will find them completely lame. Customer service at the Hatfield is usually good, but my last visit there was a disappointment - the bathrooms were trashed, and someone's kid had obviously taken a whizz in the auditorium.
But it's a good deal. If you're a parent and you want your kids to sincerely appreciate marine biology, and if you can afford it, take your kids to the Oregon Coast Aquarium before you take them to the Hatfield. Get their excitement and enthusiasm going at the big aquarium, then when they've mastered some of the basic background information and are hungry for more, hit them with the heavy academic stuff at the Hatfield. Otherwise a lot of what the Hatfield has to offer will be lost on them.