Wasn't really a longtime goal, but watching Lloyd Bridges in "Sea Hunt" probably kindled the interest. 
I was working in the pipe shop as a pipefitter 3/c. Used to watch the divers when they dove on the ships alongside. As luck would have it, three vacancies in the Diving Locker occurred as a result of transfers and a retirement of a chief. Call went out for volunteers, I applied and made the cut along with 2 others.
Next came the "tests" to see if we were capable. 1. swim the length of the pier without fins. 2.A trip to the recompression chamber where they took us down to the equiv. of 120', on the way back up to "the surface," stopping at 25' and breathing pure oxygen for 20 minutes to make sure we wouldn't suffer from oxygen poisoning. 3. Dressed out in a MarkV diving suit and dumped over the side of the pier to walk around on the bottom. This was done to make sure we wouldn't become claustrophobic. Now this event was the tricky one. I was first into the water with the only instruction given was that the air valve for the suit was located front, right, near my waist. I'm on the bottom listening to instructions over the intercom speaker located in the helmet.
"Back straight out" came the message from the Chief. Okay, no problem - yeah, right. Again, "back straight out" and I answered back, "back straight out." "Move to your right" - "Move to your left".
Well, unknown to me, I wasn't moving anywhere but deeper into the mud and silt - waist deep. I was sure I was following all the commands from topside but all I was doing was digging myself deeper.
One final command, "back straight out" and I answered back "I am backing straight out." The chief said, "Well take your bubbles with you." "Hmmmm. I guess I'm stuck in the mud, chief." They pulled me out of the mud having a great laugh at my expense.
I passed the claustrophobic part just fine. With all the marching in place in the mud, I stirred up the bottom reducing visibility out those ports in the helmet to zero.
Once back up on deck, and observing the next diver, I found out that had I increased the air-flow through the suit with that air valve, it would have inflated enough to allow me to walk across the top of the mud - 35 pound boots, 64 pound helmet and breastplate, 120 weightbelt plus the canvas/rubber suit which seemed to weigh a ton.
Two months later three of us are TAD to Diving School in Subic for 8 weeks and we became hardhat divers. After school, most all the diving we did everyday was in SCUBA gear. One of the greatest times in my life I'll always remember fondly.