Whitewater boats are slow.
You might want to get a specific ocean kayak. I spent a couple years in Hawaii. The sit on tops are nice, becuase you can jump into the water and launch. Instead of getting in on the beach and trying to push yourself through the shore break. They call the sit on tops "sit skiis".
I got a Ocean Kayak Rapido. It was about 10 ft. It was fast. I took an AMP there, but surfing on my wave ski was a lot more fun, so I rode the rapido most of the time. The whitewater boats have so much rocker that they are slow. The AMP has very little rocker, and was just under 8 feet. It was one of the fastest playboats, but it was slow compared to the sit skiis.
If I went back to Hawaii. I would get a Cobra strike. Get a surf specific boat. They will perform a lot better. There is a wavesport surf kayak.