This facility is quite small, just a couple of minutes down the road from the excellent Oregon Coast Aquarium, but the exhibits are of a fairly high quality. Well worth a visit for a zoo nerd! The city of Newport, Oregon, actually has a third aquatic establishment in the shape of Oregon Undersea Gardens but it is a single large tank and only takes 15 minutes or less to tour.
In spite of @snowleopard urging me to vist Undersea Gardens, I declined. He did talk me into stopping by Seaside Aquarium later in the day and I would not have had time for it if I had gone to Undersea Gardens. He could have fit all four in because he eats on the road (fast food drive-thru) and... how shall I put this... has a looser interpretation of what the numbers on the speed limit signs mean.