I have carried my tenor on with me on a number of flights, although not to Hawaii, without any problems.
I used to just carry it on and not make a big deal.
The last few times I have taken the ukulele with me up to the counter and specifically asked if there is any problem carrying the ukulele on board. Of course I'll state that I have flown various airlines without a problem, but I just wanted to make sure. The kicker is that if they say no, you have to be willing to hand it off to someone to take back home. And we have been able to have our son drive us to the airport. If I get asked when boarding, I'm hoping I can just give the agent's name who said it could be carried on.
I don't think under any circumstances would I check an instrument on a plane as baggage. If it were valuable there is no guarantee it would ever arrive and if it did... in how many pieces. However, this subject has gotten me thinking about a concert size for travelling.
John