Saturation Dive Team Officer-in-Charge (OIC) Mac McDowell faces his greatest challenge yet, leading the team into a critical Cold War mission. With a security clearance above Top Secret, Mac and his off-the-books deep-water espionage group must gather Russian intel to avert world war. Join nuclear-submariner Mac as he extreme-dives to a thousand feet, battles giant squids, and proves what brave men can achieve under real pressure, the kind that will steal your air and crush the life out of you. Operation Ivy Bells: A Mac McDowell Mission updates the popular bestseller by Robert G. Williscroft, a lifelong adventurer who blends his own experiences with real events to craft a military thriller that will take your breath away.