There's not much to add beyond all the very strong reviews that Captain Joel has received from other TripAdvisors.
Our group was very taken care of. Captain Joel and crew were excellent and enthusiastic guides for the amazing Na Pali coast.
On our particular day, we took the morning ride (departs 7:30am), and we managed to see dolphins (both bottle nosed and spinner varieties) and turtles. Even a couple glimpses of a humpback whale.
The snorkling was pretty uneventful because the big waves had reduced the visibility in the cove, but the remainder of the trip: seeing water life, touring the coast, riding the rough waves, eating a simple lunch were all awesome.
I really did feel it was one of the best values on the island. $99 for a half day jam packed with lots of attention, great site seeing, and physical thrills was totally worth it. Loved my experience here. I would highly recommend over the boring-looking catamarans that embarked on the exact same route as us.