The guide would periodically go back outside and throw buckets of fish food into the water causing the fish to literally charge the boat.
We were on the first boat of the day so the guide said the fish would be particularly active. Wow. These submarine tours have been running for more than thirty years, as long as this has been a protected area, and have stopped in the same three places many times a day for all these years.
This is what one of the frenzies looks like.