We did so many fun things during our two weeks in Hawaii on Oahu and Maui that it is difficult to say what my favorite activity was. Although my response might be different on different days, I think if I was hard-pressed to provide an answer to the question about my favorite activity, it would often be snorkeling in Hanauma Bay.
I had heard many fabulous accounts regarding snorkeling on Hanauma Bay Nature Preserve from people who had snorkeled there many years ago and from people who has snorkeled there relatively recently. Some had even stated that it is the one thing that one must do on Oahu. At the time of this writing, TripAdvisor reviewers had reviewed it with a "thumb up" 86% of the time and it is ranked #15 of 124 Honolulu attractions.
One of the things that I had heard about snorkeling in Hanauma Bay was the number of fish that were so easily accessible to the snorkeler. Years ago, people fed peas and other things to the fish and this brought even more fish of the more aggressive species up close to the snorkelers. Improved conservation efforts have eliminated this practice and the park ranger warned us that we'd not see as many fish up that close if we were used to that from years ago, but I was still very pleased with the number of fish and number of species of fish that we were swimming alongside. These photographs of the fish don't do their numbers justice because I tended to use video more than still photographs for the more impressive sightings.
I had never snorkeled before this two-week trip to Hawaii and I became a much better snorkeler by the end of the two weeks. Hanauma Bay was a good place for a beginning snorkeler to practice because of the protected and relatively calm water and because of the many places with sand bottoms and shallow water that I could stand to figure out what I was doing without touching coral or rocks.
We arrived at Hanauma Bay just a few minutes after the 6 am opening of Hanauma Bay and I'm glad we got up early enough to do that. We got one of the closest parking spots in the main parking lot to the park's entrance, but more importantly, we avoided the mob of people that would show up later that morning. There is normally a video to watch about preservation of the ecosystem at Hanauma Bay, but the staff was not fully available at 6 am, so we were instructed to review the instructions on personal, marine life, and ecological safety in the entry building before descending to the beach.
Because we snorkeled at Hanauma Bay early in our trip before we had decided to buy own own snorkeling equipment, we needed to rent some and that rental shack was not open until around 6:30 am. Fortunately, we had one snorkeling kit of our own we had purchased near Waimea Bay and we were able to set up on the beach and enjoy some wading in the water until the rental shack opened. The Hanuama Bay rental snorkel sets were reasonably good ones. They were not as good as the ones we'd purchase or the ones we were provided at Shark Encounter, but they were better than the ones we were provided on a couple other snorkeling excursions we took.
I cannot believe how quickly the time went by. We snorkeled for over 3 hours to just past 9 am, but it felt like we had been out there much less time than that. I also felt like I had so much left to see. We had other plans for the late morning and afternoon and so needed to leave. I was surprised at how busy the beach had become in those three hours, but was even more shocked when we ascended back up the paved trail to the park entrance and saw the long line of people curling around the entrance and onto the sidewalk in front of the park. Whereas we had been able to walk right into the park at 6 am, there was a lengthy wait by 9 am. Part of this was probably due to the film, but I also don't think that Hanauma Bay would be nearly as much fun with all those people snorkeling and on the beach at the same time. The main parking lot was also full and people were driving in circles waiting for a spot to open.
Although I was disappointed in having to leave, I realized that if I ever have the opportunity to visit Oahu again, I'll make it a point to visit Hanauma Bay on multiple days as soon as it opens (6 am). The lesson I learned from this experience is that it would be better to visit Hanauma Bay multiple times in the early morning hours for smaller sessions than to visit it once for a long session. Two to four hours at Hanuama Bay on 2-3 early mornings would be far superior to 8-12 hours there at a single time. Snorkeling is best when there are fewer snorkelers and they all know how to calmly float and watch the fish and let the fish swim around them with confidence. As the number of snorkelers increases, and particularly just one flailing snorkeler, can scare most of the fish away.
Hanauma Bay Nature Preserve is currently closed on Tuesdays as part of their conservation efforts. The admission and parking costs are very reasonable and well worth it, especially in the morning when so few others are there. For people who have their own snorkeling equipment, the overall cost of the visit is very small. It is also ideal for beginning snorkelers, but offers interesting sights for everyone in a picturesque environment. For more experienced snorkelers, the water farther out into the bay and beyond the reef that breaks up the outside rough waves, greater challenges are available.