For 8 days that is way ambitious. I assume you are starting/finishing the
charter at the Sunsail marina on the north coast of Raiatea? If so, Raiatea and Tahaa share a
lagoon and you could easily spend the entire time not going outside the reef visiting the 6 or so key sites around the two islands.
But if you really want to see as many places as possible and don’t want to relax/explore in place then pick either
Bora Bora OR Huahine as the other island to visit. You use half a day for each
passage, so it’s not worth trying for all four islands.
As noted in another thread, Bora Bora is on everyone’s bucket list so is hard to pass up, while Huahine is much less touristy and uncrowded with equivalent beauty.
Save a bit of time and hassle by paying for pre-provisioning - all your
food will be waiting in bags in your
boat when you arrive (yes, you do need to pack it away yourself and that can take a few hours). Bring as much alcohol as
import rules allow (in fact, bring more, and if they actually check and pull you up on it the tax will still be less than the cost in country). Plan on
buying baguettes and fruit and if you have
kids ice cream. Bring your own snorkels and masks to be sure they fit and
work, otherwise check very carefully the
gear the
charter company provides so you don’t find out during your first swim that your mask
leaks or the snorkel is munted.
There is another thread that I don’t
recall that discusses charting from Raiatea in great detail.
Have fun!
If you can arrive the night before the start of the charter and spend the night on board you’ll be able to get away earlier the next day.