Well, been and done a few things.

Went to Pearl Harbor at 7am and quite a few people queuing already at that point. did manage to park in the nearest lot so that was handy. There were coachloads of tourists turning up throughout the day and a good 200+ in the queue (even with the rain) by the time the gates opened.

I bought a passport for around $65 so everything was included (well, not the $11 for the photo of you on a newspaper that is taken before the Bowfin or the $25+tax+??? for the photo(s) taken before the Missouri or the $10 for the flight simulators at the airplane museum or a guided tour - a least one very knowledgeable volunteer who was at Pearl Harbor when it was attacked). Booked the Arizona for 11am but was given a ticket for 7:30am when I collected it - a lot better time wise.
Did that for up to an hour (including video) and then the Bowfin sub.
Then headed over to the Mighty Mo before the Aircraft Museum.
Saw everything and had lunch and it took to mid-afternoon. Wasn't rushing.

Drove to Hanakuma Bay the following morning (did have a tour booked but never saw the shuttle bus to pick me up so had to drive).
Bit of a drive out there with one sign telling you to turn right NOW! Too many roadworks at present that are slowing things down (fine before 9am but a lot of tailbacks when I was coming back).
$1 for parking, $7.50 entry fee and you had to watch a video before heading to the beach.
$1 each way for the trolley thing or a 3 minute walk down and up hill.
Was supposed to have snorkel hire with the tour but couldn't see where to hire from (I would definitely bring a mask as I couldn't see clearly enough underwater without one) - bit hazy. Not too bad through the surface although the waves do chop the water up.
Anyway, quite a few fish about ranging from little ones to foot long ones, some within a foot of the shore.
Quite a bit of power in the waves and it was hard to stand up in places due to the force of them hitting you.
You can avoid the coral as there are plenty of sandy areas around them although you'll need to swim to go further out where things like turtles may be (I don't like getting too near the coral - nervous about hitting it with my feet)

Did a good 2 hours there but you could easily spends a lot longer depending on how much you're seeing.
Lots of people there but never any space problems and a number of fish at once especially around the edge of the coral / sandy areas.

Drove to Diamondhead after that.
$5 to park at the base of the trail but I used a car park just after the road up to it (college or something? No charge for it).
$1 if you walk up.

Rather warm and not much shade in places. 90C and a mixture of concrete, rocky trail, winding rocky trails, steps, a tunnel, even more steps, a spiral staircase and a little bit of ducking to get out of a bunker (or there's an easier way after the first set of steps).
A bit more of a climb to the top but amazing views.
Takes 20-30 mins depending on how fast you're moving. Quite a few people in front of me so I could only go at their pace. Hard going as well in the heat - was sweating quite a bit afterwards!


Rather a lot of homeless people about. The parks seem full of them with their tents etc. Did see someone sleeping in a hole on the beach the first night I was there.
Got to see the cops handcuffing someone as well (4 cars and a silver 4x4 which may have been overkill).