Throw in an Army unit, too. My father-in-law’s 75th JASCO - Joint Assault Signal Company - 3rd wave. Ran the communications lines between units at minimum. In many landings they also served as Forward Artillery Spotters (called Observers than).
You can find out about the Signal Corps ops in the Pacific in the official history volumes, by organization, known as the “Green Books”.
Father-in-law is still alive and sharp at 94. Don’t know how many Purple Hearts he got in the Pacific campaigns (Saipan, Eniwetok, Tinian, etc. Heard he had at least three.
Later rose to become a Lt. Col. with the Army Security Agency and turned down a Brigadier General position to be with his family and soon deceased wife.
Signal Corps frontline units suffered up to 60-75% casualties in many of the Pacific campaigns.
The 75th was the only Army unit to land on Iwo in an assault wave. Combat Engineers (Navy Seebees if I recall correctly), lost a whole company on the beaches due to a mix-up in request for personnel (they needed one man and got a whole company, largely unarmed by mistake. Took the brunt of a Japanese suicide attack).
The Army brought the troops in on assault transports. A late cardio-rehab friend of mine, Gen. Bruce Jacobson, was the commander of one of those transports.
Everybody fought or served at Iwo, though the Marines did literally all of the ground fighting.
We must never forget any of them. Back then we had real military leaders and politically incorrect soldiers, which is why we won the war.
I didn’t see your Comment until after I posted.
My Dad was an Army radar specialist who went in D+1.
Please check out my Comment #27.
I have no idea what unit my Father was attached to, but he and his lieutenant and squad were bunked all alone with Marines on their transport ship.
Is it possible radar guys were in Army Signals, too?