From Wikipedia
Origins
“Although not formally founded until 1962, the modern-day U.S. Navy SEALs trace their roots to World War II.[7] The United States Military recognized the need for the covert reconnaissance of landing beaches and coastal defenses. As a result, the joint Army, Marine Corps, and Navy Amphibious Scout and Raider School was established in 1942 at Fort Pierce, Florida.[10] The Scouts and Raiders were formed in September of that year, just nine months after the attack on Pearl Harbor, from the Observer Group, a joint U.S. Army-Marine-Navy unit.”
My co-worker joined the Navy when he was 18 and stayed four years, then went to college. When I knew him, he was the CEO of one of the largest paging companies in the world. He was fairly credible.
Since his service spanned the actual formation of the SEALS, I would suspect he was grandfathered in. After the Bay of Pigs, he focused on mixed gas diving.
I wish he was here to answer questions. I am not military nor do I follow the JFK plotline. I just thought I would pass on his story.
If I can find the book with the full flechette story in it, I will post it.
Wikipedia