Simon was the boat captain of the Hang Loose boat tour (and I believe owner) and we went out for 2-1/2 hours and saw lots of spinner dolphins and got a nice tour of the coast. Since we went the end of March, the whales were on their way out (we knew it was late in the season) but we saw numerous spouts and tail slaps. Didn't see the magnificent breaches like on the Pacific Life commercials, but again we were aware this was late in the season for Hawaii. Captain Simon and the crew were very knowledgeable, friendly, etc and made the trip fun.
We like the set up of the boat - it wasn't a cattle boat. Had 2 levels, one open and one covered so you could choose your spots and move between them. It was a catamaran hull so was more stable. It leaves from Honokohau Harbor, just north of Kona.
All in all it was the best to hope for, going the end of March. Would go with Hang Loose again definitely .