Drowning was the cause of death for a skydive instructor and a novice student who were killed when they overshot a landing zone at Dillingham Airfield and came down about 300 yards off shore, the medical examiner's office said.

Erich "Max" Mueller, 69, died as a result of asphyxia, or suffocation, due to drowning, the medical examiner's office said. Saori Takahashi, 33, of Japan, died as a result of anoxic brain injury, or loss of oxygen to the brain, due to drowning, it said.

Further testing would be necessary to determine if Mueller experienced a heart attack or some other type of incapacitation on the way down.

Employees with Skydive Hawaii, the company Mueller worked for, said it was possible the skydive veteran had become incapacitated due to heart attack, stroke or an aneurysm before the pair landed in the water.

Toxicology and other types of testing is still anticipated, the medical examiner's office said.

Calls to the Federal Aviation Administration about the investigation into the incident were not immediately returned.

Frank Hinshaw, president of Skydive Hawaii, told The Advertiser Saturday that he watched Mueller go limp after the main chute was deployed. He said he watched Mueller and Takahashi, who were jumping in tandem, suddenly begin to drift toward the ocean instead of heading into the wind over the landing field.

Hinshaw said yesterday that he was disappointed the results did not immediately indicate whether Mueller had experienced a medical problem.

"We were hoping this would have unlocked the mystery of what happened to Max. Unfortunately, this didn't," Hinshaw said. He said he is still convinced "something happened to disable Max."

Mueller had appeared in good spirits and even jovial before going up in the airplane to 10,000 to 14,000 feet, he said. He said pre-jump video showed Mueller smiling, laughing and even throwing a shaka sign. It did not appear that Mueller was experiencing any medical difficulties, he said.

However, after the main chute was deployed, Hinshaw said Mueller no longer appeared in control of the parachute. Instead the tandem team drifted away from the landing field eventually landing in the ocean.

"What happened between the time the parachute opened and the landing I still don't know and I'll never be able to find out," he said yesterday.

Mueller has been described as a fitness buff who worked out daily. Mueller was also a "very disciplined, very exact" skydive instructor, Hinshaw said.

Skydiving instructors are required to receive a physical examination every two years in accordance with the rules of the United States Parachute Association, of which Skydive Hawaii is a member, Hinshaw said. He did not immediately have the date of Mueller's last physical but did say he submitted that information to FAA investigators.

A memorial service for Mueller is planned for 5 p.m. Sunday on the grounds of Skydive Hawaii, Hinshaw said. There will be a missing man skydive formation at sunset. Friends of Mueller are invited, he said.

Reach Loren Moreno at lmoreno@honoluluadvertiser.com.