Public swimming beaches can be found at Titlow Park (just south of Narrows Bridge) and Wapato Lake Park (S. 72nd St. and Sheridan Ave.), where a lifeguard is present in the summer. American Lake Park, south of Tacoma [1] near Fort Lewis, also has swimming.
There are two parks with fishing piers on Commencement Bay. Also known as Sundial Park for the giant stone timepiece there, Commencement Park is the quieter of the two. Marine Park has more amenities, with a long narrow strip of shoreline with open grassy areas, picnic tables, a fishing pier, bait shop, and snack stand. Fishing for dinner may not be such a smart idea, however, since Commencement Bay is one of Puget Sound’s "hot spots," where the bottom fish and even salmon have shown unhealthy levels of toxins.
Links:
[1] http://www.moon.com/destinations/washington/south-puget-sound/tacoma