I disagree, dinner at Ohana's takes longer than you expect. I would say that at 6:30 you may stress a bit about making the cruise. Typically the dinner at Ohana's is about 1.5-2 hrs....depending on how much you eat, servers, etc. Typically, plan on waiting 15-20 minutes to get seated at a minimum, then it takes another 10-20 or so for drinks and apps to come out....they come out in spurts, so you won't start your main courses about 30 minutes in....depending on how quickly you get the meats you want, if you want second or thirds, you are sitting a bit because they aren't making to order, you are just waiting for the right skewer to come by. Than, you have to end that portion, have dessert (again 10-15 minutes to get it to the table) and your outprocessing/paying, etc. Add to this any travel times and I would say to have a stress free dinner shoot for 6 ish (if you can) and enjoy your meal.