My grandfather served in an Acorn unit in WW2, which were US navy units that landed with Marines, set up airfields, and then guarded and operated those airfields in the Pacific. I've been trying for quite a while to find information about them, but it seems to be scant online. For example, they are mentioned in the Wikipedia page on Argus units (which I gather performed flight control on Pacific airfields), but there is no such page on Acorn units themselves. Is anyone here familiar with them, and can anyone recommend any books or other sources about their activities in the war?
According to the unit history of some of the Naval Construction Battalions (NCB or seebees) ACORN was code name given to pre-planned landing strips.
If your relative helped build them, might he have been a seebee? Do you have any more info on what your grandfather specifically did?
http://www.history.navy.mil/museums/seabee/UnitListPages/NCB/074%2520NCB.pdf
My dad served in what was called ACORN (RED) ONE - the unit name was originally LION ONE - changed to ACORN, papers say he was sent to the Solomon Islands on a secret war mission. He left SF on a private ship SS Somelsdyk from September 1, 1942 to the Solomon Islands. He was there until June 6, 1943, he was sent home with Malaria. Guadalcanal was in August of 1942, so he evidently landed right after the marines. He was an aircraft repair mechanic (sheet metal, not engines). He never told us what he did, but his records indicate that he was being bombarded day and night. I got his records from the US Navy using his SS number. Then used that to get Fold3 (private site with Military Info) to find his unit's exact history. With a few drinks in him, he told my brother's some crazy stories about shooting and direct combat in WW 2. He NEVER talked about the war, he told us he was a tugboat captain. As for information on Acorn Units - it is almost non-existent.