I would have to agree with many of the posters. While Bonaire is by far the most convenient shore diving that I've ever experienced and Curacao is the most similar in diving to Bonaire, picking a #2 is tough for me. I can personally attest that all of the following locations have very good shore diving:
1. Curacao - I just got back from Curacao a couple weeks ago. This is my second time there and the diving (coral, fish, etc) is very similar to Bonaire. The main difference is that the reefs are typically just a slight bit further from shore and the convenience of tank drop off and pick-up may not be as easy depending on where you stay. Unlike Bonaire, I usually just rent tanks a la carte rather than get a package. Many of the more popular dive locations have dive shops nearby. If you want to use Nitrox, there are not as many locations on the island that carry it and you may have to let them know in advance so they can order the tanks. I personally use Ocean Encounters for Nitrox because they have multiple locations around the island where I can get tanks and I only have to go through the paperwork once. (i.e. C-card, Nitrox card, waiver, etc.) Mark and Suzy at the DiveBus are really nice folks too. There are many good dive locations on Curacao, a few of my favorites being Alice In Wonderland (Playa Kalki), Porto Marie, Jan Thiel Baai, Tugboat (Caracas Baai).
2. Big Island of Hawaii - Hawaii provides a somewhat different experience than the Caribbean. Having dove quite a bit in the Caribbean, I like the change of scenery, fish and other creatures that Hawaii provides. The Southwest side of the Big Island offers some excellent opportunities for shore diving. One of my best dives ever was here. In a single dive I saw a pod of dolphins, numerous turtles and eels, an eagle ray, and a very rare monk seal swam around me for 5-10 minutes! It was amazing!! My only recommendation is take your time packing up after diving to give your body some time to rid itself of some nitrogen (I typically wait at least an hour). The main road is 1500 ft or more in elevation in some spots. I've never had a problem with this. My favorite shore diving places here include Place of Refuge and Kealakekua Bay (the closest place to rent tanks is next to Kona Boyz (about 10-15 minutes away). Also, it's fun to rent a kayak from the locals at Kealakekua Bay and paddle over to Captain Cook's Monument for a day of snorkeling. Just remember to bring fresh water, snacks, and a water camera as there are no facilities at the monument. Oh... and if you do decide to spring for a boat dive, definitely do the Manta Ray night dive. It's a world-class diving experience.
3. Maui - Maui has some very nice shore diving. Unfortunately, when I was there the surf was a little heavy due to a storm, so the water was not as clear as normal. Nonetheless, I saw many very large green sea turtles, eagle rays, mantas, and other pelagics. Although I only dove sites near Wailea, my favorite site was Ulua Beach.
4. Monterrey, CA does have some nice diving, but it IS very cold compared to these other locations! Breakwater is a fun and easy dive, but you better bring or rent a very thick wetsuit or a drysuit.
I've heard good things about CoCoView on Roatan from friends, but I haven't been there yet. I think that or a liveaboard may be my next trip.
