One of the most interesting experiences Oahu has to offer is the North Shore shark dives. Several companies (at least two) offer this service for the most adventurous of traveler where you can snorkel or scuba dive in a shark cage or without a cage.
Although jumping off the boat three miles offshore with sharks circling around sounds dangerous, it is not. The sharks are just curious and not aggressive, and there is a master diver present with knowledge of shark behavior who will keep the divers and snorkelers safe. It is a three to four hour trip and the best part is that after the invigorating swim, you get to enjoy the town of Haleiwa with all the local foods and dinks to replenish your spent energy. Bucket list or not, it is a once in a lifetime experience.
We used Hawaii Adventure Diving, a small local company, and you can find their website here.
Below is the short video of our dive with our friends.