Iv done one in S.A.
it was good but the sharks obviously knew the story, they could turn up and get a snack or 2. Meant they were very (too) docile. There was nothing scary at all about the scenario, as it was more just a big fish swimming past.
Dont get me wrong, i dont regret going, but as a bit of an adrenaline junkie, it was all abit too similar to an aquarium for me.
I ran with the bull in Pamplona around the same time, which was awesome.