only just saw this now. So probably too late.
I have sailed in Mana lagoon about 10 years ago in Sept, Windy every day in 5.5m2.
Just doing tacks in that area with the red lines below, you can cross the reef but need to time it right with the tide, as it is really shallow, waves were not really rideable though and closing out.
Didn't get to Cloudbreak but you can get someone to take you by boat (need to check the rules of when you can go in for sail there though).
Anyway still good fun to windsurf at Mana, beautiful lagoon
