As an American destroyer cruised off the waters of Japan in clear weather in the early hours of Saturday, only a few dozen of the crew of 350 were likely to be awake: standing watch, keeping the engines running, manning the bridge.

Then, Navy officers with decades of experience at sea say, there were probably minutes of sheer terror aboard the Fitzgerald before the collision with an enormous container ship that killed seven sailors.

“My guess is they suddenly saw the lights of the other ship coming toward them and tried to veer off,” said retired Adm. James G. Stavridis, whose book “Destroyer Captain” recounts his time commanding a similar ship in the mid-1990s. “Suddenly your ship is sinking under you. It’s terrifying.”

Navy leaders on Sunday hailed the efforts of the surviving sailors who struggled to seal off compartments and pump out the water that poured in through gaping holes torn in the starboard side.