The Regional Planning Chair has been trying to secure hotel rooms for the incoming teams and was able to get 100+ rooms at $180 a night or so. This is a bit much for many teams, but with it being the peak season, this is all that could be secured. Details are still being worked out as to who to contact, etc., but when they are finalized, your team will be officially notified.
As for a team social, yes a luau is being planned for Friday evening. The University of Hawaii College of Engineering is also planning on a student/parent meet and greet with food on Thursday evening - not quite certain of the size of this ‘event’ however (for planning team dinner purposes on Thursday that is). They will be sure to announce more later.
As for other things to do, Diamond Head is nice and cheap (just make sure everyone can handle the trek up and down in the heat). Pearl Harbor is rather somber, but the Swap Meet (Flea Market) at Aloha Stadium is within walking distance on Wednesday or Sunday to buy things you won’t find elsewhere for quite cheap.
Right in Waikiki are the Honolulu Zoo and Honolulu Aquarium (the Aquarium is quite small and the Zoo is, well, not something people come to Hawaii for).
As mentioned before, Hanauma Bay is quite impressive, but closed on Tuesdays and parking often fills fast.
If you want to go to some of the less touristy beaches, consider going to Kailua town. If you make your way through the mountains, you can stop at the Pali Lookout for a great view. If you go around the island instead, there is also Sea Life Park to consider which is like a mini Sea World.
If you head to the North Shore, you can consider the Polynesian Cultural Center, but it’s a little pricey and not open on Sundays.
You might also consider the very easy hike to Manoa Falls for the nature lovers which is at the back of the valley where the competition is being held.
Other than that, hope everyone making their way here is able to have a great time during their stay!