My wife and I do extensive shore diving in Hawaii, primarily on Maui with some on the Big Island. You should know that at some dive sites the entry is a little dicey due to rocky bottom or other reasons, but there are some use friendly ( and sometimes crowded) sites. I suggest you contact one or more of the dive shops on the Island ( you will need to get air tanks and lead from them anyway, and perhaps other rental gear.) I commend to you Jack's Diving Locker or Kona Honu Divers, both near or in Kailua-Kona. And there are others. As far as doing these dives, a newly certified dive pair can certainly shore dive. Just remember to:
a) be sure you are familiar with the gear you are using
b) do a thorough buddy check
c) plan your dive and dive your plan
d) be sure to have a dive flag ( Hawaii will fine you if you don't, and it is a safety issue)
e) carry a safety sausage or other surface signaling device
f) have someone on shore who knows where you are diving, your basic dive plan, and when you are coming back
g) ask the local shop or other divers in the area about the site and learn all you can before diving there. A lot of locals shore dive, and there is a good chance that you will meet up at a site with someone who is familiar with it.
h) if you remain a little anxious, you can probably "rent" a dive master for a lot less than the cost of a 2 tank boat dive for just one of you. That is always an option
I would recommend that drop a little money to go on the boat for the manta ray night dive. Kona-Honu, Jack's, and other shops do it , and it is worth every penny!!
Have a great time!
DivemasterDennis scubasnobs.com