thanks, sbm12. I took your advice and booked biz class for whatever days I could find. Not optimal, but better than nothing. There was plenty of availability in Y to Guam, but not onwards to Yap or Palau.... but at least I have NRT-YAP / ROR/NRT. I'll try to either get another award YAP/PNI/ROR or just buy the YAP/ROR.
I found someone else's recommendation to use
www.asiares.nwa.com ..... (worked great !) although there was more availability there than I could book using SkyMiles
As for diving - only one of us is a diver, so I'm afraid that a liveaboard might be too boring for me ....... although I've only started my investigation .....
PS cool photos !