capybara:
[...] Is Kahalu'u diveable or only good for snorkeling? Any suggestions for easy shore dives not too far from Keahou/Kona in case we want to poke around a bit after our AM boat dives?
Outside the breakwater it's diveable, but (largely) uninteresting. Just north of where you're staying along
Alii Drive is Mile Marker 4, a popular shore dive. Further north is the Old AIrport. Both are covered
here.
capybara:
[...]Favorite restaurants nearby? We also want take a day to drive to Volcano National Park, then to Hilo for a 2:30 helicopter tour, and go to a luau at 5 pm in Waikoloa. Is this doable, or are we being crazy? How long does it take to drive there usually? Any suggestions for quick/interesting stops along the way to Volcano? What should we do while we're in the park (given the time limitation)?
If you plan a day trip to Kilauea, and still make a 14:30 helicopter ride in Hilo, you're in for an
early start.
Kilauea is about 100 miles away from where you're staying, and the road is 2 lanes the whole way. Count
on 3 hours to get there. To get some idea of what to expect from Kilauea, the
USGS has good information about
the current conditions there.
My personal preference when we take guests to see the volcano is to head down there timing our
arrival for late afternoon, so that we can see the surface flows after dark. Take sturdy shoes, flashlights
and drinking water - sometimes its a bit of a hike. But, when the pali (hillside) is flowing well it's the
best show in town.
Hilo is another 45 minutes past Kilauea.
There's
no way you'll make a 17:00 luau in Waikoloa, unless you have the helicopter drop you off.
As for restaurants, close by is Jameson's, which has a great view, and somewhat spotty service and
food (sometimes it's good, sometimes not). Further north along Alii Drive, "in town" there are quite a
few restaurants. One of the more polular ones is
Huggo's (in the interests of full disclosure, it's owned
by friends of ours). And there's the ever-popular
Kona Brewing Company a bit further north, behind the
FIrestone dealer. My wife and I very much like Bangkok House across the street from there in the King
Kamehameha Mall for Thai food.
For fine dining you'll need to head to one of the resorts along the Kohala Coast or to
Merriman's in Waimea.