So, I'm wondering if keelhauling was something that happened frequently or not. I mean, it sounds like a pretty severe punishment, and I'v already looked it up for a bit, but it never mentions how bad it really was and how frequently they did it. The sources I found also didn't mention why anyone would get keelhauled in the first place. Would stealing be enough? Would ingorning an order be enough? I'd really like to know!
Keelhauling was a traditional punishment in the Dutch navy. I can't really speak to its frequency, but perhaps /u/eternalkerri can -- they mentioned it in a post here:
You may also be interested in this podcast and discussion thread on the Golden Age of Piracy: https://www.reddit.com/r/AskHistorians/comments/2cbyjk/