We originally booked the 4.5 hour snorkel tour to West Maui that allowed you to snorkel at two locations. Unfortunately, due to high winds, they called us to reschedule, which I appreciated because it showed that they cared about our snorkel experience. The only other tour we were able to do was the Mala Xpress snorkel, which was a two hour trip to the Mala Wharf.
We caught the catamaran off the beach by Whaler's Village, and it took us about 20 minutes to get to Mala. We were quite surprised because the location was just where we had lunch the same day. We could have literally just swam out from the ramp itself instead of taking a 20 minute boat ride. However, we were still excited to get into the water and snorkel. Right before we got into the water, one of the crew members noticed that we brought our own full face snorkel masks. She proceeded to tell us why she didn't like them (according to her, they could fill with carbon dioxide if they got stuck to your face, and you could die) and then finished it off with "good talk." It was a bit snarky and unnecessary, as many people use full face snorkels and love them.
By the time we got into the water, we only had about 45 minutes to snorkel for the two hour tour. The staff that was in the water with us were fantastic, taking pictures and pointing out sea urchins and the one turtle that we saw. We didn't really see very many different kinds of fish... maybe 3 or 4 types. There was a group of 4 of us and two of us tried Snuba (a combination of snorkel and scuba) which was an extra $60 each. Even though they were about 10 feet lower than us in the water, they also didn't see a lot of sea life.
For the price of the Mala Express tour and the amount of sea life you actually saw, I don't think it was worth the money and time. We went to Black Rock the next day, snorkelled for 5 minutes and saw much more than we saw at Mala... for free.