Landing in Kona on Thursday and scheduled a bunch of dives with Jack's and KDC. Any particularly enjoyable sites to report back on? I've scheduled some night dives, manta dive, and also considering a long-range dive with Kona Honu.
Since I'm here a couple of weeks, I've forgone the $250 charter dives in favor of shore diving (tanks from Kona Honu) and snorkeling. Conditions the first eight days were amazingly calm wind and seas, though I heard from divers at Kona Paradise that the visibility was slightly less than the week prior, which as covediver mentioned, was apparently outstanding. A brief wind and rain storm whipped the surf up for a day or so, leaving fairly milky conditions, and it took 3 or 4 days to calm back down enough to open up many shore sites. The last 3 days have once again been calm, though the swell is just a slight bit higher still- enough to motivate a bit more care about entry and exit spots, and swell timing.
If you're new to Kona shore diving, there are a lot of great, accessible dives, but many of them are off lava bench shoreline, which is great for ease of entry and exit, great for viz, and great for diving right up tight to the shore, but also can present challenges when the swell is up even a slight bit. That's when it becomes critical to pick an entry/exit spot that isn't amidst a maelstrom, and won't get you dragged up and over the bench, or over shallow rocks below the bench. It's not hard to find sites with such spots, but really important to do so. Also pays to have felt-soled booties (Walmart has them, though size selection is hit or miss; some dive shops may have them too) when walking on wet or smooth rocks.
Two really easy spots are Honaunau Bay/Two-Step (20 miles south of Kailua) which is a highly visited snorkel and dive site for good reason (nice coral for Kona), and Hookena (another 2 miles down the highway), which has a nice beach to the left, but IMO kinda drab undersea conditions (go right from entry). Both of these are places the dolphins visit, though I've not seen or heard of dolphins this trip, which is a first. Get to both early, like 8AM (esp Hookena with limited parking), if you want a shot at good parking. Honaunau is divable when most others aren't because it's at the back of a horseshoe bay. You can do two or three dives there to see it all. If you like BBQ, Island Jake's just before the turnoff to Honaunau is open Fri/Sat/Sun and shares a bldg with a poke restaurant, or Super-J's just before that for lau lau (kahlua pork wrapped in ti leaves) are good options in the area.
There are a number of easily accessible sites along Ali'i Dr just south from Kailua Town - Pahoehoe Beach (enter channel at the right, go right, 4-Mile, Kahaluu Beach Park (swim out past the surfers, and go right or left), and Keahou Bay (Sheraton side), which if you have the stamina to swim out and into the area in front of the hotel, is a pretty cool spot. A number of the condo developments along the shore side of Alii have bench entry access, though for the most part you have to be staying there. Viz tends to be a little worse along the Alii sites than elsewhere, but there is also better and extensive coral. Can be pretty fishy too.
Crescent Beach/Dog Beach/Honokohau Harbor is also a very easy entry from the small sandy beach, though you have to cross 30 yds of boulders to get to it. In addition to being popular for the protected entry, it's at the mouth of the main fishing harbor so there's a good chance of seeing tiger sharks, and rays I believe are common too. I've never ventured out or deep enough to get into the main tiger zone, and I find the shallower area closer to shoreline not as nice as many others.
I had the best dive of the trip today from the cove just beyond the far end of the runway at Old Airport, just north of town. It was sunny, clear, and very fishy, with more large parrot/trigger/unicorn/ and surgeon fish than I've run into elsewhere, and even a very big Spanish Hogfish, as well as the usual swarms of damsels and tangs. Good coral abounds in 20 ft of water - go right from the cove for an endless series of deep water canyons along the bench, or out and slightly left for lots of coral, and lava fingers with arches and undercuts, and many interspersed sandy patches. The steep slope drop-off is not far out, esp if you've gone to the right. The cove entry is one of the few where waiting for high tide makes it notably nicer. I went in at the low high this AM (Shark Fin Rock was completely out of the water), and it was fine. The next high would have been a foot higher.
There are a few spots between the airport and Puako which is 30 miles north of Kailua (watch for wild goats along the highway), including access at some of the lava desert hotels and developments along the way, but none that I've found noteworthy. Puako end-of-road is a popular dive and surf spot, with lots of shaded parking. On flat-sea days the entry is pretty easy though you have to navigate over and around some lava shallows to get out to the edge of the underwater bench - some (me) go in from the small channel on the far right, others go out through the narrow cut in the boulders just beyone the shoreside trees. On less calm days it looks and feels more gnarly than it really is, but the sloshing and eddy currents can be disconcerting at first. I've dove Puako probably a dozen times and always had just meh viz up against the underwater lava bench, which is where I like to explore, but it's a very nice area to dive. The best canyons and arches are to the right, but the area to the left, out off the beach, has lots of good structure as well. Don't overlook the tops of the benches if conditions permit, there are a lot of holes and small ridges, and it's usually very fishy. The benchtops are deeper when diving to the left. Don't let anyone talk you into entering at any of the other access signs along Puako Rd - you have to cross shallow benchtop with breaking waves. Go all the way to the end. Don't run over the turkeys, and don't let them beg.
There used to be a great website for Hawaii: shorediving.com. It's been folded in crippled form into zentacle.com, but you can still find shorediving.com on the wayback machine (web.archive.com). You have to go back to 2018 or so to get past all the re-directs to zentacle. You can find locations, aerial photos, and diver reporting on lots of dive sites on the Big Island and the rest of Hawaii.