All,
Wow... I didn't expect this kind of reaction from this crowd. Let's see if I can give a bit of a different perspective.
I started diving in Hawaii in 1979 (that's where I was certified). Since then I've dived all over the Pacific (most of Micronesia [Chuuk, Yap, Palau, Rota, Majuro], Australia, Fiji, Vanuatu, Solomons, PNG, Manihi, Rangiroa, Bora Bora, Moorea), Christmas Island, Indonesia (Lembeh, Komodo, Rajat Ampat, Bali, and East Kalimantan), Maldives, Cocos, and much of the Caribbean (although nothing recently). I'm not listing this out to sound arrogant, but rather to set the context for the following statement:
Good diving in Hawaii is as good as what many of the places above offer, and (in my opinion) better than virtually everything the Caribbean has to offer (and yes, I liked Little Cayman, Belize by liveaboard, the ease of diving in Bonaire, the critters of St. Vincent & GR, Cozumel, the sharks in the Bahamas [by liveaboard])). The one exception I might make to this is the fairly new "shark dives" that members of this board are raving about off of the Bahamas (with the Tigers, etc.).
I still choose to do a week of diving in Hawaii each year (and can't wait until by kids are old enough - this will likely be the first place they dive as well). We usually do a 1 week in Hawaii and then another 2+ weeks somewhere else. Sometimes we even combine these (Hawaii is a great place to break up a trip to Fiji, the Solomons, or Tahiti).
Having said this you need to get away from the crowds and find a good operator. There are so many things to do in Hawaii many of the operators feel like they are going to be competing with other activities so they optimize for efficiency (and volume) vs. quality and showing off the really unique aspects of the Hawaiian Islands.
Hawaii has a huge number of indigenous fish, and more relic fish species than anywhere else on earth.
Some of the world class diving in Hawaii (not in any particular order):
1. Nihau (The "Forbidden Island") off of Kauai. This is done as a 3 tank all day dive by two of the operators (Bubbles Below and someone else, can't recall the name) on Kauai. One of the only places in the world where you can dive (fairly regularly) with Monk Seals. The occasional Oceanic Whitetip shark as well as the amazing underwater geography (The "Arch" makes an incredible picture when schools of fish swim through it). The schools of Butterflies here are larger than most places in the pacific. Note: they only dive this in the summer during the calmest days (and even then the trip back is "an experience...")
2. Any of the "Fish Aggregating Devices" off of Oahu or Maui. These large Navy buoys are natural aggregation points for drifting sea life, which in turn attracts small schools of fish, which attracts larger fish and even some of the open ocean predators. Very interesting diving (sit under a buoy and wait to see what shows up). A number of operators will offer this kind of trip, but only once they are comfortable w/your skills (these devices are usually 1-3 miles offshore). Note: there are several operators now offering "chummed" dives for sharks outside the 3 mile limit in Hawaii - haven't done this yet so can't comment on the experience.
3. "Turtle Reef" off of the Mauni Lani Hotel, Kahala coast, Big Island. The Mauna Lani raise and release Green Sea Turtles right off their property each year on July 4th. These juveniles usually hang out on the reef for several years before venturing off. This means there is a constant 30-50 green sea turtles hanging out in one area - makes for a great dive as on average you can find 7-8 turtles on a dive, and on occasion as many as 20-25 (depending on time of year).
4. "South Point" on the southern tip of the Big Island (only reachable on the Aggressor). Southern point of the Hawaiian islands - stuff comes swimming buy at an amazing rate. I've personally seen sailfish, marlin, oceanic white tips, hammerheads, and 2 whale sharks here. This can be an amazing place to watch big stuff.
5. West coast of Molokai: very hard to get to, but you can be rewarded with schooling hammerheads (in the dozens - so not quite Cocos numbers, but still really cool). No operators currently dive this regularly, but you can charter a boat in Maui or on Molokai to get you there if you are motivated. Some of the most pristine diving I've done anywhere...
6. Southwest coast of Maui: if you do this with a good operator (I highly recommend Mike Severns http://www.mikesevernsdiving.com/) you'll see many of the unique underwater life in Hawaii. If there is a frogfish along the coast, they will find it. They showed me the biggest frogfish I have ever seen anywhere - literally the size of a football. They also can show you things on the inside of Molokini that most operators either don't know about or don't have the patience to find. I just did this with them again about 3 months ago and it was a great dive (2 eagle rays, lots of cleaning stations, etc.)
7. Just north of Kona on the Big Island: For years Dive Makai was the best dive operator here. They would show you the truly unique animal life that no one could find (or try to find). The operation has been sold but the couple running this boat now seem to follow the same philosophy ("only two speeds: slow and stop..."). Only operation that has have ever been able to show me a Tinker's Butterflyfish (actually 3 of them together - completely unafraid of divers - these fish don't come shallow, start searching for them 110ft). All kind of critters live off the west coast of the Big Island - but you need an operator that wants to show you these unique animals, not just get you in and out of the water and back to the dock.
Oahu actually offers some of the best diving in Hawaii (sunken submarines, hammerheads & other sharks, etc.), but it's not readily available to tourists. That's because there are so many operators that base their business on volume. Most people dive 1 day or maybe 2 at most, so almost all of these operators just run a set schedule each week (Monday - "Landing Craft," Tuesday...). You really need "a friend w/a boat" to get to the really good diving off of Oahu.
- Matt (aka: One Yellow Tang - my favorite fish in Hawaii)
