No not the effort to make a dud of a pistol, but one of the last true amphibious operations to take place. 56 years ago today, January 28th 1966, Operation Eagle commenced. It was a joint operation with the 3rd Marine Amphibious Force and the South Vietnamese 2nd Division. It was also launched in conjunction with Operation Masher to the South (essentially a mirror of Double Eagle but involving the Army). One interesting point is the USMC unit make up of forces involved. It was essentially a reinforced regiment. But all of the battalions were from different regiments. The infantry battalions involved were 3/1, 2/3, 2/4, and 2/9 plus two artillery battalions and two companies of reconnaissance. Just strikes me as unusual to have a such a mix.
The goal was to have the Marines and ARVN 2nd Division engage the NVA and VC in the area while Operation Masher’s forces attached the base areas. The plan called for the artillery to be set up at hill tome Special Forces camps followed by a beach landing. After securing the area the marines would move by helicopter to cut off any retreating NVA/VC.
Not counting the previous reconnaissance work D-Day of the operation began on the 28th and the following patrols went on until February 17th. There was little Heavy fighting though as most encounters would break contact after hitting the marine units. While there were some delays due to weather the operation went according to plan for the most part. However it turned out that most of the enemy forces had left the area the week prior to the start of the operation. In response Operation Double Eagle II was launched two days after concluding the first operation in an attempt to destroy the NVA forces that had been missed.
If you want to see more details on the uniforms I have the same article but with the uniform part up over at Geared Up
Here are links to the PDF version of the official USMC publication. The first was directly from the USMC but when I went back a day later its was a dead link so here is a second one to archive.org.
Here are some other links I used.