My experience:
Hawaii- flew Jetstar, picked up a 9'3 PSH, wrote 9ft in big letters on the board bag, $120 to get it booked through to Perth. The Hawaiian baggage guys had heaps of aloha and couldn't have cared less. No dings or damage but did pack it with lots of foam.
Bali from Perth - Virgin last year, 2 short boards, 1 SUP, all clothes shoved into boardbags. Made sure I printed out the rules from the Virgin website as the ground crew at Perth Airport are only contract staff who didnt have a clue and were a bunch of Sge Shultzs saying I had to pay $20 extra per kilo ( 30 kilos worth

) until I produced the document.
Bali from Perth- Air Asia - IDIOTS in a word. They base everything on weight. So I rang them...
Me: hi there can I take a standup paddle board on the plane?
AirAsia: Whats a standup paddle board?
Me: look into my eyes, not around the eyes....
Air Asia: Er, maybe, how much does it weigh...
Me: around 10kg.
AirAsia: OK thats good.
Me: Yeah but other airlines focus on the length so it can fit in the hold, so could it be 14ft?
AirAsia: we base it on weight. If you read our blah..........
Me: I know, I read it, that's why I'm ringing you.
AirAsia: well we base it on weight, I'm sorry I can't answer that question for you.
So I didn't risk it with the nupties at the airport and ended up renting one with Jankie for a half day and getting some waves on the Nusa Dua side. Enjoyed the pool with the kids and didnt miss it (much)