yeah, Hawaii is not the sort of place where there are dive ops at lots of hotels with onsite diving, docks, and dive facilities. Even if you can find one I wouldn't necessarily go with it. Good chance it won't really be the resort you'd prefer, or one of the better ops, or both. Just a theory, but I'd guess you don't hear about whatever few hotel ops there may be on the dive boards or Undercurrent because if they exist they cater to casual divers who might do a couple dives on vacation, vs. more serious divers.
As far as the Big Island, there are a few areas where resorts are concentrated, and a few harbors where the dive boats leave from. And well, it's a big island, and traffic into town can suck in the morning. So if you don't like going far in the am you probably don't want to stay in one of the nice resort complexes further north and try to leave from Kailua harbor in downtown Kailua-Kona. You could stay downtown someplace close to the harbor and stroll to a dive boat there in the morning, but I don't think there's anyplace in walking distance I'd want to stay on my honeymoon. The King Kam is right there and I've stayed once, but it seems to have gotten dumpier and more depressing over the years. Or stay someplace around town and have a relatively short commute and maybe get picked up by the op, but I don't know where is nice to stay around town. I'd look at the ops that leave from the other harbors, then look at resorts in the closer resort clusters. I've stayed in Waikaloa which is nice but I think the Mauna Lani area and resorts are even nicer. The Four Seasons is more off by itself and certainly nice, and maybe the closest to Honokohau harbor, I thought some ops left from there.
Personally, I'd stay at the Mauna Lani Bay hotel, or maybe the Orchid, if there's a good op leaving from Kawaihae. Or maybe the Four Seasons and find an op leaving from Honokohau. Sort of depends how much money you want to blow.
