We just happened upon them!!! It’s at a place called Electric Beach, I highly recommend going! There is an electrical power plant on the beach and it puts out hot water, so it attracts a lot of wildlife. We saw a bunch of fish, sea turtles and those spinner dolphins, but I’ve heard of people seeing sharks and even seals and sea lions!
We went a time before the day we saw the spinners, so it really just depends on luck sometimes! So, good luck! :)