The Coast Guard has formally reprimanded a member with 23 years in uniform for flashing a hand gesture tied to white supremacists during a live TV interview featuring his boss.

He was upbraided in administrative letter of censure signed by Capt. John Reed, the head of Hurricane Florence response efforts in Charleston, South Carolina, when the unnamed officer formed the “OK” hand signal during MSNBC’s Sept. 14 “Live with Ali Velshi" broadcast.

“While your actions may have seemed funny and playful to you, they clearly showed lack of maturity and inability to understand the gravity of the situation, namely the preparation and response to Hurricane Florence, a declared disaster,” wrote Reed in the Oct. 5 letter, which the Coast Guard provided to Navy Times.

His admonishment was first reported by The Post and Courier, which identified him as a lieutenant.

The Coast Guard declined to provide his rank or rating to Navy Times but the services typically do not name junior officers or enlisted personnel who receive merely administrative sanctions for wrongdoing.

Velshi was interviewing Reed about the changing path of the deadly storm and the tactics the Coast Guard employs to mitigate that when the lieutenant, seated at a table behind the captain, looked directly at the camera and formed the “OK” sign before moving it across the right side of his face.

That sparked an explosion of outrage on social media because the symbol has become linked recently to white supremacists and ethnic nationalists, even if it’s long been associated with signaling that everything’s fine, too.

OK’s strange path to alt-right politics and “white power” symbolism began as a joke.

In a 2017 troll campaign on a popular 4chan board, participants tried to bamboozle liberals and agitate the mass media by spreading a hoax that neo-Nazis had commandeered OK as a secret signal.

The problem was that some in far-right and white nationalist circles earnestly adopted it.

Noting the migration from online stunt to sincere hate symbol, Mark Pitcavage, a senior research fellow at the Anti-Defamation League’s Center on Extremism, weighed in, saying that his organization was updating its understanding of the gesture while cautioning that it’s “not a reliable signifier and no one should assume anything about the use of such a gesture unless there are other unmistakable white supremacist signifiers in that context as well.”

Within the maritime services, the “OK” sign also has long been associated with the “circle game,” tomfoolery that involves a quick, but painful, swat by a prankster on an unsuspecting victim.

Without specifying the lieutenant’s intent, Reed’s administrative letter of censure hints that the unidentified man’s motives weren’t racist, just juvenile and premeditated.

The captain notes that an unnamed public affairs specialist had directly cautioned the lieutenant about the controversy behind the gesture before the live broadcast began, “yet you went ahead and decided to play a game as a leader in our Service. In doing so, you embroiled the Coast Guard in a political and social controversy that reverberated at the highest level of our Service and Department.”

In an email to Navy Times, Coast Guard District 7 spokesman Lt. Cmdr. Ryan Kelley said that an internal probe by Coast Guard Investigative Services determined that the letter of censure was the best sanction for the lieutenant.

Although Capt. Reed in the written reprimand tells the lieutenant that the letter will neither be filed locally with his unit nor end up in his permanent records, Kelley explained that the officer’s actions were documented in his annual evaluation report.

“This annual evaluation report is a document that is a primary consideration for future jobs or promotions that this member might apply for or be eligible for in the Coast Guard,” Kelley said.

Although the lieutenant was immediately removed from all storm response efforts, his stunt created a significant distraction from the efforts of the Coast Guard and partner agencies battling Hurricane Florence, Kelley said, and “the perception that this gesture created, regardless of the intent, is not only unprofessional but contrary to all three core values of the service, Honor, Respect, and Devotion to Duty.”