“Bakuhatai: The Reconnaissance Mission of the USS Burrfish and the Fate of Three American POWs”
Published on HivePostify by @kingneptune · Wed Sep 02 2026
“Bakuhatai: The Reconnaissance Mission of the USS Burrfish and the Fate of Three American POWs” is the National Archives account of one of the most remarkable—and tragic—early combat-swimmer missions of World War II.
National Archives — “Bakuhatai”
What happened
On August 18, 1944, the submarine USS Burrfish (SS-312) surfaced off Gagil Tomil Island, Yap, in the Caroline Islands. Its mission was highly unusual: conduct photographic reconnaissance and deploy a small UDT reconnaissance team to obtain detailed information about beaches and reefs in preparation for planned American amphibious operations.
Five UDT swimmers went ashore:
John Ball Emmet Carpenter Howard Roeder John MacMahon Robert Black
They wore swimming trunks, camouflage paint, carried knives, fins and beach-survey equipment, and used a small inflatable boat.
The shallow reef prevented the boat from getting close enough to shore. The swimmers therefore had to conduct the reconnaissance by swimming toward the beach.
The critical mistake
The mission encountered a combination of problems:
The reef was too shallow.
The surf was difficult.
The operation was occurring under a full moon rather than the originally planned new moon.
American air attacks had increased Japanese vigilance.
The UDT team had only recently been assembled and had limited time to train together.
These factors made the operation considerably more dangerous than planners anticipated.
Three men—Roeder, Black and MacMahon—were ultimately left behind when the Burrfish had to withdraw.
The submarine's commanders rejected an immediate attempt to recover them because it was approaching dawn and Japanese radar activity was about to begin. A plan was made to return the following night. But the weather deteriorated, making another boat launch too dangerous. The Burrfish eventually departed for Pearl Harbor.
The Japanese captured them
American intelligence later intercepted Japanese communications indicating that the three swimmers had been captured.
The Japanese called them “bakuhatai”, essentially identifying them as members of a demolition unit rather than submarine personnel. The Japanese interrogation report indicated that the prisoners revealed some basic information concerning UDT organization, mission, equipment and capabilities—but apparently did not disclose information about future American operations.
And then they disappeared.
They were never recovered from a POW camp, and their remains have not been located.
The National Archives concludes that Robert Black, John MacMahon and Howard Roeder were likely among American prisoners executed in the Palau area, probably around September 4, 1944, although the evidence does not establish the exact circumstances with absolute certainty.
Why this story is particularly important
This mission connects several strands of the history we were discussing earlier.
1. It was an early submarine-launched UDT operation
The Burrfish demonstrated that a submarine could deploy a small team of highly trained swimmers onto an enemy-controlled island for reconnaissance.
The National Archives describes the mission as demonstrating that a small group of trained frogmen could be deployed from a submarine for operations against an enemy-held island.
That concept is fascinating because it anticipates later special-operations methods involving submarine insertion and clandestine maritime reconnaissance.
2. OSS and UDT were actually merging
This is perhaps the most interesting connection to your previous question.
UDT 10 had just incorporated members of the OSS Maritime Unit.
The OSS swimmers who had been diverted to Hawaii became Maritime Unit Group A and trained together with UDT 10. Lt. Arthur O. Choate, from the OSS Maritime Unit, became commanding officer of UDT 10.
Two of the three men ultimately captured—Robert Black and John MacMahon—had originally been assigned to the OSS Maritime Unit and were on their way to Cairo before being diverted to Hawaii.
So the Burrfish mission wasn't simply a conventional UDT operation.
It was an early fusion of OSS clandestine-swimmer expertise and Navy UDT capabilities.
3. The mission had strategic consequences
Here's the remarkable part:
The capture of the three swimmers contributed to the cancellation of the planned American invasion of Yap.
Even though the prisoners apparently revealed very little useful operational information, their mere presence on Yap indicated to the Japanese that an American operation against the island might be imminent.
So the reconnaissance mission intended to help prepare an invasion instead helped convince American planners not to invade Yap.
Meanwhile, the intelligence gathered for Peleliu and Angaur had limited usefulness because several planned beaches could not be surveyed.
The bigger historical picture
The Burrfish operation sits almost exactly at the intersection of the traditions we were discussing:
OSS Maritime Unit → clandestine intelligence + swimming
UDT 10 → underwater reconnaissance + demolition
USS Burrfish → covert submarine insertion
Yap reconnaissance → intelligence collection immediately preceding amphibious operations
1944 → three frogmen captured
Tags: #genealogy#gems#unitedstatesnavy#usnavy#udt10#oss#worldwar2#ww2