If you're staying in Waikiki and want to do a long walk/ hike there's a great view from Diamond Head. To enter the park it is a $1 per walk in visitor or $5 per vehicle fee that is cash only. The hike once you get to Diamond Head will be 1-2 hours and includes stairs, so plan accordingly. On the website there is info for how to get there by bus.
We have gone scuba diving every time we have gone to Hawaii together. So far, Reef Pirates Diving is our favorite company to go with! Scuba diving is one of our favorite vacation activities to do together.
Our first trip together, we did some snorkeling at Hanauma Bay. There are shuttles and transportation from Waikiki hotels. See the website for more info on transportation and rentals.
There are a variety of different kinds of tours that Hoku Hawaii Tours offer. They are all full day tours. On our first trip together, we did one of the eco tours. The eco tours are more active and nature based. We did stand up paddle boarding, jumped into a waterfall, a tasting at a macadamia nut farm, and saw some sights. While we have only done the 1 tour, we thought it was well organized, had a great guide, and enjoyed all of the stops. If this doesn't sound like the right tour for you, take a look at some of the other ones they offer!
Another fun day trip we did on our first trip. A great way to learn about all of the different Polynesian cultures. Very interactive and immersive.
Kualoa Ranch doesn't just do weddings! There are all kinds of activities such as horseback riding, ATVs, and scenic tours. Dennis has done ATV riding there. Did you know part of Jurassic Park was filmed at Kualoa Ranch?