Thought I would update this as I have been there now.
I arrived HNL for 2 days on Halloween, that was an interesting sight!
Did Diamond Head hike - great views, not that hard, Iolani palace tour and surrounds - interesting with Hawaii Five 0 connections, Aloha Tower - run down dump.
Caught buses up and down, very easy except for "exact change"
Next day drove up the East coast, saw the Nuanu Pali Cliffs lookout, Makapuu Point lighthouse walk and then drove up to Turtle bay resort...no surf at all.
Drove back to HNL and flew over to Kauai, stayed at Poipu for 2 nights, drove to Waimea Canyon, did lookouts and hiked Waipoo Falls.
Next Day did NaPali Cliffs sailboat tour, Very good but not the best weather, then back to Lihue and did Chopper flight over entire island doors off small chopper is the best way.
Then up to Princeville for 2 nights, did first bit of Kalalau Trail Hike, not easy but do able. Hanalei, other beaches
Down to Hawaii Big Island, Stayed at Captain Cook, Manta snorkel first night, next morning kayaked to Kealakekau Bay Capt Cook Monument, snorkled, very good only people there due to early start.
Drove on St Benedicts Painted Church, Place of Refuge Village, South Point and over to Volcano.
Next day did Kilaeau iki Hike across old volcano, saw sulphur banks and Jaggar museum, lookout of glowing cone. Dinner at Volcano House.
Next day Chain of Craters Rd and drive around...due to new lava flow SE corner of island was restricted...so didn't see any live lava.
Next day up to Hilo, Mauna Kea up to top on tour, observatories, sunset, stargazing.
Next Day Hilo town, Tsunami museum, Iolani Astronomy museum
Next day up to Waipo Valley Lookout, over to Waikoloa Marriott, Nth Kohala scenic drive Pololu lookout
Next day to Kona, see town area
Back to HNL, stay at Hilton Rainbow Tower
Pearl Harbour, $59 for Sub, Aviation Museum, Missouri and Pearl Harbour itself. Had pre booked Arizona tour on internet prior.
Caught bus out there $2, spent all day, still not long enough, bus back $2
Next day up to National Memorial of the Pacific or Punchbowl via local bus then back to Ala Moana for a look
Dukes for dinner
Back to Aust.
A good trip, needed more time at many places, many more hikes and tracks to explore but as always run out of time.
I live in Nth Qld so a lot of the scenery reef/rainforest was similar for me except for the Volcanic bits and the Na Pali Cliffs.