Big Island Divers and Kona Honu Divers are both great to dive with but sign up for their advanced trips they cost a little more but less crowded. Shore diving the Puako area is very good House 56, House 40 and Catholic Church are all good sites and you can rent cylinder from Blue Wilderness in the Queens shopping center. Blue Wilderness also runs an RIB out of Puako that hits these sites as well. Kohala Divers out of Kawaihae are usually less crowded and will most likely be the only dive boat on the sites they use. If you want to try shore diving on the Hilo side use Bill at Nautilus Dive Center he’s been shore diving that area for about 35-40 years and is a wealth of information.