A popular Tacoma Narrows Bridge dive is to locate one, or some, of the large cement mooring blocks that were used to hold cranes and barges in place during the construction of the bridge. These rectangular blocks are massive cement structures that have a vague appearance of semi truck trailers when encountered underwater. They run parallel to the bridges and perpendicular to shore. Underneath these blocks are many large caverns that house some very large lingcod, giant octopus, wolf eels and other denizens.

There are many blocks below the bridge at both ends but the most easily accessed are a series of the blocks on the east side side under the bridges ranging from 40-80' deep. A popular way to dive them is to drift into them during a very mild current near slack.

Enter the water near shore in about 20-30' deep water and descend to 60-70' until you encounter a block and then explore upwards from that point. Make sure you are upstream far enough that you can get to your desired depth before reaching the bridge, but not so far that you never make it on a small current. Safety stops are most safely accomplished by following the bottom contour eastward toward shore and explore ledges and kelp beds while drifting along the shoreline.