Hacker gained experience as a Navigator and Tactical Coordinator in SP-2H "Neptune" and P-3C "Orion" aircraft through numerous operational assignments in the far reaches of the Atlantic[2] and Pacific Oceans and Mediterranean Sea.

In 1988, at the completion of his assignment as Commander, Naval Base San Diego, Rear Admiral Hacker retired from the U.S. Navy.

Rear Admiral Hacker was the first Naval Flight Officer (NFO) to be selected for Flag rank in the United States Navy.

On November 3, 2005, the "Commander, Task Force 67"[9] headquarters building located in Sigonella, Sicily was dedicated in his honor.

After retiring from the Navy, Rear Admiral Hacker worked at financial-services firm USAA as assistant vice president for policy service, at the organization's western regional office in Sacramento.

On December 28, 2003, Rear Admiral Hacker[11] died from complications relating to chronic lymphocytic leukemia, a disease which he battled for 12 years.