While at the North Shore in Oahu, Hawaii, I was able to go free diving with sharks. No cage, no scuba, just simply a mask snorkel ans fins...and my GoPro.
Went with One Ocean Diving, and both Ocean and Juan were great.
We went out with the boat for a few miles, and set up to drift with the boat. Right away, after the first jump in, there were about 17 sandbar sharks. Will post some photks and videos soon...great experience.