There is no shortage of ocean or beautiful places on the Big Island. We went to see Kealakekua Bay, where you can apparently ocean kayak with dolphins. Although we weren't able to go out kayaking (thank god), it was a nice little spot to check out.
We did go snorkeling near Place of Refuge. It was beautiful! This snorkeling spot is a bit more advanced, as there are more waves and it is deeeeep water. You go in off the rocks and boom! You're in the water and you can't stand up. That was a bit too much for me.