Of the areas that I frequent, this is my favorite entry;
"The Keyport Naval Undersea Warfare Center (NUWC) is on the west side of the entrance to Liberty Bay. A seaplane float extends 100 feet northwest from the end of the pier and mariners are requested not to exceed 3 knots when passing it. Several buildings are prominent at the station.
A torpedo test area extends off the shore between Brownsville and Keyport NUWC. Flashing red lights on navy range vessels between Keyport and Brownsville and atop a building at the seaward end of the southern building at Keyport NUWC indicate torpedo firings, or that noise measurement tests are in progress, or that conditions are generally hazardous to mariners. When lights are flashing, mariners should not enter the test area. Mariners near the area should stop engines, or other equipment generating underwater noise, such as depth sounders, because some torpedoes are guided by noise and may be attracted to the boat noises."
A couple of years ago, we were heading to Brownsville via Agate Pass, as we passed Keyport, I noticed a little repeating pattern shading the test area on my B&G Chartplotter with Insight charts. Curious, I zoomed in, and then in some more, until the individual elements of the pattern became recognizable... little torpedoes!
