The floating, acoustic surveillance devices are used in anti-submarine warfare. The Oregonian reports that in a modified environmental assessment for Northwest training and testing, the Navy increased the number of planned sonobuoys from 20 to 720.
They would be in areas at least 12 miles offshore from Alaska, Washington, Oregon and Northern California.
The Navy acknowledges that deploying more of them is likely to harm endangered leatherneck turtles. It's accepting public comments until Feb. 2.
In addition to more buoys, the document also details additional "maritime security operations" that weren't reviewed in the earlier environmental assessment, possibly including escorts for submarines, search-and-seizure exercises, and anti-piracy missions.