Kuipo - we've just returned from an 11-day cruise on Aloha.
Yes there is a Hawaiian ambassador on board, he holds lei making classes from 5-7 each/most evenings in the Cultural Centre on Deck 7 (twixt atrium and shops). You don't need to book (just turn up when you fancy) but there is a charge. He also holds hula classes (no charge). The Cultural Centre is an open area on Deck 7 with glass cases full of information and artifacts and a film playing on a loop, starting at the firt volcanic eruption that created Hawaii. Cruisers can choose to sit and watch the film in one sitting or just stop-by every day and take it all in in bit-size pieces.