Nine people were onboard the large military aircraft when it slammed into the bay at 2 pm near Marine Corps Base Hawaii.
All nine people onboard made it to shore without injury, officials said.
Wild photos showed the Navy plane floating in shallow water after the military mishap.
What led up to the crash-landing wasn’t immediately clear and an investigation was launched.
The plane, a P-8 Poseidon, is used for military surveillance and intelligence gathering.
It is manufactured by Boeing and features many of the same parts as 737 commercial jets.
The downed aircraft is part of the Skinny Dragons of Patrol Squadron 4 stationed at Whidbey Island in Washington state.
At one point, patrol squadrons were based at Kaneohe Bay, but they currently deploy to Hawaii on a rotational basis.
Marine Corps Base Hawaii is located about 10 miles from Hawaii’s capital, Honolulu, and houses approximately 9,300 military personnel and 5,100 family members.
Conditions were cloudy and rainy around the time of the crash and visibility had dropped to about 1 mile, Thomas Vaughan, a National Weather Service meteorologist in Honolulu, told the Associated Press.
Aircraft expert Peter Forman believes that bad weather and shorter runways may have played a part in the mishap.
“The pilot probably didn’t put the plane down exactly where he wanted to on the runway,” Forman told local TV outlet Hawaii News Now.
“It’s probably a combination of all those factors put together.”
Witnesses were shocked by the sight of the plane in the water.
Diane Dircks, 61, and her family were on a pontoon boat trip when the rainy weather cut the excursion short.
“We went running over to the end of the dock, and I took some pictures,” she told AP.
Sirens rang everywhere, and her daughter was able to give her a closer look since she had binoculars.
“It was unbelievable,” she said.
The U.S. Sun contacted the Marine Corps for comment.