I'm in Maui

[Ross]

My favorite is mile marker 14 south of Lahaina.
Although I saw a manta ray at Sugar beach.

[Werbo]

15-20 minutes south of Kehei.

http://www.hawaiisnorkelingguide.com/ahihi_kinau.html

[reefbyremote]

The best we saw was Kapalua north of Lahaina. Its good this time of year. In summer Honolua is supposed to be great, but I understand it has higher surf especially in winter.

[Duffer2]

Originally Posted by Ross

My favorite is mile marker 14 south of Lahaina.
Although I saw a manta ray at Sugar beach.

Second this. Great spot. Also Mekena Landing.

[hillegom]

Maluaka beach
There are bathrooms there. When facing the water snorkel left around the rocks. Fish and corals galore, even an arch and turtles. Go when the surf is down.