There are many companies that offer snorkel and scuba dive cruises on the Big Island of Hawaii, but my personal favorite is Fair Wind Big Island Ocean Guides
Fair Wind makes daily snorkel and scuba dive cruises (and whale watch cruises in season) along the South Kona Coast of the Big Island, departing from Keauhou Bay, just a 15-minute drive from Kailua Kona.
Fair Wind operates two boats. The Fair Wind II is their older boat, having entered service in 1994. It's a 60-foot aluminum catamaran with covered deck, 15-foot water slide, high jump platform and most of the amenities you'll find on other similar vessels in Hawaii.
Their other vessel, the Hula Kai, is, quite frankly, unlike any other boat you've been on and, without question, the most modern boat sailing in Hawaii today. Fair Wind has definitely "kicked it up a notch" with the Hula Kai.
Related Features About Fair Wind Big Island Ocean Guides
Fair Wind Big Island Ocean Guides
78-7130 Kaleiopapa Street
Kailua-Kona, Island of Hawaii, HI 96740
Fair Wind Big Ocean Guides website