With 75 years having passed since the attack on Pearl Harbor of Dec. 7, 1941, the Hawaiian lagoon remains synonymous with destruction. But, in the weeks and months before the surprise assault, even as war raged around the world, Pearl Harbor represented pretty much the opposite. The soldiers and sailors stationed in Hawaii had a plum assignment, and the nation saw the harbor as proof of American naval power.

When LIFE Magazine profiled the Navy in October of 1940, a year before the attack, that celebratory tone was evident throughout. And, at the center of that celebration was Pearl Harbor, as a LIFE crew was allowed to sail along on maneuvers off of that base.

“The U.S. Navy is good,” the magazine proclaimed. “It is the great fighting creation of a people whose genius is not warlike but mechanical.”

Though the reporters admitted that the fleet was not yet entirely ready for war, it was already a great collection “of mechanical marvels and human skills.” Pearl Harbor was being transformed into “a first-class base like Britain’s Singapore or Malta” and each battleship was “a city of 1,200 sailors,” who lived their lives at the pace of the bugle, whether performing practice exercises (like the first-aid drill seen in the second image above) or making good use of their leisure time.

Ahead of the anniversary of the Pearl Harbor attack, TIME commissioned freelance photo editor Sanna Dullaway—who has previously worked with photos of Indy 500 racing, Queen Elizabeth II and much more—to colorize several of the images from that story, presenting a new and unique look at that suspended moment before war began.

Sanna Dullaway is a photo editor based in Sweden. See more of her work here.