By April 23, 1944, Redfin, badly shaken from her compromised rescue attempt, was making good time home through Makkasar Strait. Flier, of course, is finishing her trials and is having photographs taken.
Robalo had entered her patrol area in the South China Sea. She had to skirt a little south to avoid a very shallow reef known as “Dangerous Ground”, and started looking for targets. On her first day, she sighted a submarine, but decided not to attack, since it was quite likely it was an American or Allied submarine. Since it did not attack Robalo, they simply passed each other.
Robalo approached Southern Indo-China (now known as Vietnam). In her war patrol reports for the day, she noted passing through an oil slick (sometimes a mark of a damaged or sunken ship or submarine) and a small sailboat.
Then, at 5:30 in the evening (1732 hours, for the purists!) the Robalo was surprised by a “Betty” that had snuck up on them by hiding in the glare of the sun. A “Betty” was the American nickname for a Japanese Bomber. Robalo dove quickly, hearing the first explosion before she got fully underwater. They dove so quickly in fact, that the air intake valve to the engines wasn’t closed fast enough, then jammed partially closed, allowing water to spray into the engine room. The XO noticed on the “Christmas Tree” (the panel of lights that told the diving officer whether all of the important valves and hatches were closed) showed that valve was neither open or closed, and went back to help close that valve by hand.
If Robalo thought they had narrowly adverted a disaster, they were wrong. At 55 feet under, before the periscopes had fully submerged, the Betty struck again, striking Robalo so close, she was thrown violently to one side, then lost dive control.
She plunged wildly, and the men scrambled to re-gain control, because if they didn’t, she would be crushed by the weight of the water. They manged to stop the descent at 350 degrees, but the problems were only just beginning.
The “normal” damage was noted: dishes and lightbulbs smashed, blades of fans sheered off, the cork lining of the walls cracked and fallen in places.
More serious damage started to be reported: the SJ Radar was completely out of commission, the Conning Tower hatch leaked, the JP Sound Head, the hydrophone that picked up the underwater sounds was out of commission and stiff, the hydraulic steering was badly leaking so Robalo could steer slowly, and she leaked a lot of oil.
She surface quickly, (thankfully, the seas and skies were clear), and checked the exterior. The picture wasn’t any better. All external running lights were smashed, the pelorus (used to take readings and bearings off of landmasses to figure the position of the submarine) was destroyed, two antennae were down, the antennae trunk was flooded due to its smashed insulator caps, causing problems in the radio room. The Number One Periscope was shattered, flooded and useless. The Number Two Periscope’s low power was ruined, high power had been jarred and the field covered in black spots. Gaskets to two ballast tanks leaked, the 4-inch deck gun cap was split and cracked, the targeting sights bent beyond use, and the the auxiliary engine exhaust vents closed so exhaust couldn’t be vented outside.
A CO’s first responsibility was the care of his submarine and crew and the list of the damage Robalo sustained was enough that most CO’s probably would have turned for the nearest Submarine Base or Tender, terminating the patrol early. Kimmel decided to give his crew the chance to do as many repairs as they could. It would take over 24 hours.