At the time, the Navy prohibited married men from enlisting. So they kept their relationship a secret.
He sent for Jill, and she moved into a home outside the base. Renteria used his passes to visit her, but he wanted to fully commit to their future.
"We married in secret," Renteria recalled. "I knew I might get in trouble, but it was love."
Renteria knew Morse code, and could see their home from the hanger where he worked. He taught his new bride the code as well, and they would spend a few moments on his duty days communicating via flashlight, saying phrases like "I love you" and "I miss you."
The secret communication and their secret marriage were soon discovered. Renteria found himself standing before officers, including his commander. He told them the truth, and although he was punished and ordered to stand extra duty, it could have been much worse.
Renteria and his wife transferred to Hawaii in the summer of 1941. Shortly after, he was sent to Pensacola, Florida, to the Navy's photography school. Just months later, the United States would be dealt a blow most Americans didn't see coming when Japan attacked Pearl Harbor in the early morning hours of Dec. 7, 1941. Ships sank and diesel fuel ignited, cooking off bombs and ammunition, engulfing Pearl Harbor in fire and thick black smoke. War broke out on two fronts, and the call to arms spread like wildfire across the nation.
Renteria returned to Hawaii in early 1942, assisting with the cleanup and recovery.
Then, one day as Renteria was performing his daily duties, a lieutenant arrived with a manila envelope marked in a bold red stamp: 'SECRET.' Carrying his seabag and photography equipment, Renteria boarded a plane bound for Noumea, New Caledonia, in the South Pacific.
Renteria was soon flying covert missions over the small islands that dotted the South Pacific. His job was simple yet difficult: Find and photograph not only enemy bases, but their fleets as well. Find areas that could serve as possible landing sites or forward operating bases.
He hand delivered his photos directly to Admiral William "Bull" Halsey Jr., who commanded the South Pacific Area and later Third Fleet.
The first time in Noumea, [New] Caledonia, I was standing there at attention, waiting for the lieutenant to take the photos," Renteria said, his memory so sharp he remembers every detail as if it occurred yesterday. "I wasn't supposed to talk to the admiral - ever. ... The officer says, 'Well bring them!' I forgot about protocol and I just turned around and walked to the admiral. He says, 'From now on you bring them to me.'"
To get the proper photo, Renteria would slide the canopy of the aircraft back to avoid the glare of the glass enclosure. He felt the wind in his hair as he leaned out as far as his harness would let him to get that perfect shot.
Much of the time, anti-aircraft gunfire would pop in black smoke around the plane, sending shrapnel in all directions.
To make matters more intense, Renteria and his pilot would fly without any armament - no weapons to defend themselves - to conserve fuel.
"Of course you were scared," Renteria said. "But you couldn't think about it then. You couldn't."
Their job was to not only document the enemy, but do it and survive.
Not everyone in his squadron was so lucky, however. Still, there was no time to mourn the dead. Renteria had work to do.
He next joined Marines on their island-hopping campaign as they forced the imperial Japanese soldiers further and further out of the South Pacific. He continued to gather intel, but he also took photos of battles and firefights, landing at Guadalcanal, Bougainville and other islands.
At Guadalcanal, Renteria developed a code to keep track of his fellow photographers - men he felt responsible for. Each photographer had a clicker, a small rectangular hollow box with a thin piece of aluminum metal across it. The photographer could press the metal and when it was released, it let out a short click. Renteria would click his, and the men would click back to signal that they were OK.
One day, Renteria saw a squadron of Japanese planes flying straight at his position on Guadalcanal. Men took cover in ditches and under trees. Renteria didn't quite have time to hide, however. Instead, he crouched down and continued to click his shutter, seemingly fearless. That photo, a copy of which still resides in Renteria's collection, shows Marines diving for cover in a gulley as a Japanese Zero screams overhead.
"I couldn't get to the ditch yet," Renteria recalled, holding the photo, studying it as he remembered that day. "Oh yeah, you're scared."