pdx
HSM Pilot
I would hesitate to say "never," but as far as I know or have heard, this is true. During my tenure at NASC, there was a flight doc on swim hold for 9 weeks. He eventually made it and went on to graduate.
I was briefly on swim hold (failed the mile). The POs on staff will teach you what you need to know to get you up to par.
The OCS swim screen is just a class 2 swim qual. It wasn't too difficult (even for me). The API swimming was easy for most, but it gave me some problems because I wasn't a strong swimmer.
If you are in doubt, go to the swim hold sessions while you are in A-pool. They let me join and showed me a lot of good stuff. I still failed the mile swim and got put on swim hold later, but it only took me one more try to pass, so I didn't get rolled out of my class. Being on swim hold sucks because you have to go to swim sessions after your classes. This means you are swimming while your buddies are at home. It's just one more thing that cuts into your study time. Plus, I was always very tired after the swim hold sessions. Thankfully I only had to do it during the last week of academics (FRR class), which was relatively easy.
While spending an extra week in API isn't the end of the world, I was VERY glad to graduate in 6 weeks. If I hadn't volunteered myself for the swim hold classes while I was in A-pool, I probably would have needed extra time during API.