This is a great excursion!! We saw several dolphin pods and then got in the water to snorkel around them. It was amazing. We also saw a couple humpback whales that arrived in Hawaii a little early this year.
The crew (Katie, Jenna and Allie) was awesome. So knowledgeable and fun!
Again I found this in Tripadvisor which never disappoints. Thanks!

We absolutely loved this trip. We saw a pod of well over 100 spinner dolphins swimming all around us. None of our family had ever gone snorkelling before but they made it so easy. Crew was helpful and VERY creative with the pictures. They were very knowledgeable about the sea life we saw as well the local area. The boat ride was a blast too.+

This was an amazing day trip made better by good fortune. The boat crew and photographer were great and had a really nice chemistry with each other that the rest of us fed off of. The trip was a good amount of time and the crew was very knowledgable. I thought this would be me swimming and someone pointing and yelling dolphins are over there. However, I was able to actually get and swim in the pod of dolphins. We also was turtles, an eel, and a whale - the good fortune. And I was able to hold a live octopus which suction cupped itself to my arm - again the good fortune. It was a great excursion Just do not expect much from lunch

I live on Oahu and have snorkeled quite a bit. The West side of the island can be a little more "tricky" to safely leave your belongings on the beach, but the snorkeling is incredible. We wanted to snorkel spots we had not been and be almost guaranteed (knowing that with wild animals, there is no such thing as a guarantee) that we'd see and hopefully swim with dolphins. We ended up that day snorkeling a spot we had snorkeled before because that's also the area where the dolphins were. We knew there was a chance we wouldn't snorkel somewhere "new", so that was no problem. We swam with dolphins all around us. It was AMAZING. The crew was awesome. (They won't say anything about this, but a tip at the end of the tour is a nice gesture given how great they will treat you.) The photographer is AWESOME and you'll have great pics to show your friends and family. She will show you a small album of her work, so you have an idea of what you'll be getting. The boat is not huge, so you won't be on there with tons of people. To me that's important. We were comfortable, it's very safe (although, you're talking about open ocean and swimming with larger sea creatures, so I wouldn't bring a small child), the staff/crew are so friendly, and we had so much fun. Give them a try. I don't think you'll be disappointed!