Everyone knows, or has at least heard from any number of SEALs and others in the media, in books and in movies, that Basic Underwater Demolition/SEAL (BUD/S) training is the most physically demanding training regimen in the world. This is of course debatable, as other U.S. military courses, and some foreign military courses for that matter, might rival BUD/S in difficulty. That is neither here nor there. I am not going to argue the suck level of each in turn in an pointless attempt to find the winner of the “hardest training” award.

I am here to regale you with some training horror stories from one phase of BUD/S training—second, or dive phase—that may or may not swing your opinion one way or the other in terms of what you think is the hardest training program in the world. Either way, BUD/S is a giant kick in the jewels, as evidenced by these 10 ways that second (dive) phase almost killed me:

1. The “Ice Boat”

This truly sadistic torture device—er, “cold-water conditioning tool”—was nothing more than an inflatable boat filled with ice that trainees were made to lie in for extended periods of time. I am fairly certain my reproductive organs made their way up far into my upper stomach region in their futile attempt to stay warm and preserve my future offspring. Brutal.

2. The 5.5 nautical mile swim

This one doesn’t sound so bad, right? A leisurely swim off the coast of Coronado, California, in the warmish fall air, staring at your swim buddy for four hours straight while your wetsuit top chafes the skin off of your armpits. Throw in 65-degree water and some rolling swells, and you might find yourself seasick, like me, vomiting between strokes as you try desperately to make the cutoff time for the swim while praying that a shark bites you so that you can end the ordeal. After all, you are chumming for sharks, anyway, with your vomit. At the end of the swim, you crawl out of the ocean barely able to move, and eat two MREs to replace the 4,000 calories you just burned.