March sounds fine by me.
As for where, hhmm, I wouldn't mind if the next Invade the Rock was held in: Southwest Rocks, NSW; Ningaloo Reef, WA; Lady Elliot, QLD; on a Coral Sea Liveaboard, QLD; Eaglehawk/Tasman Peninsula, TAS; Bicheno/Bay of Fires, TAS; Margret River/Albany/HMS Swan, WA (you'll have a hard time pulling me away from the vineyards though);
All the wreaks in Melbourne, VIC; Wilsons Prom, VIC; Byron Bay, NSW; King Island, TAS (if only for the cheese); Poor Knights, NZ (can't forget our NZ brethren, eh bro?); Mikal Lematov wreak, NZ; Milford Sound, NZ; Truk Lagoon, Micronesia; President Coolidge, Vanuatu; a nice bit o'reef, Fiji; WW11 wreaks, Darwin; Great White Shark Dives, SA; whatevers good, New Caladonia; Iron Bottom Sound, Solomon Islands; PNG liveaboard; East Timor; Rajat Ampat, Indonesia; Lembeh, Indonesia; Palau, Truk Lagoon, Micronesia (yes I know i've posted it twice); Bikini Atoll; Scapa Flow, Scotland (I admit it's a little bit out of our way, but would be worth it for the single malts); Hawaii (oh dear, I'm starting to drift aren't I?), Truk Lagoon, Micronesia (see, I've posted it a third time now); Lion City, China; Victoria Island, Canada; the Great Lakes, Canada/USA, cave country, Florida................
I hope that helps.