there were 24 on the cruise, but all well placed so that everyone gets plenty of time and angles to shoot. They will do personal tours, but imagine it would be very expensive. Make sure you do the sunrise tour...the lava in the dark is amazing, and you get to watch the sunrise change the light over the while scene.
And Sunny...we are in Tucson at the moment after visiting Joshua Tree NP, then Organ Pipes National Monument...now off to Sedona, Grand Canyon, Page, Bryce, Zion then over to Pinncales National Park (the new NP) before flying out of LAX on March 15.
Andrew, you captured the lava beautifully and I can almost feel the heat and smell the steam. The volcano on the big island is truly remarkable. I believe it's one of the few spots on earth where you can stand next to lava and still be alive!