If I remember correctly you are staying at 3 different hotels. I would bring a carry on each and one checked bag. That way you can get all your toiletries and sun screen in the checked bag along with stuff for the last hotel. Pack the carry-ons with the stuff for the first 2 hotels. This way if your luggage is lost (it can't happen for the 3rd time) you will still be ok and it will catch up to you by the time you get to the 3rd hotel. For me 12 days is a long time to go without having everything you need. I don't know about you but everything takes up more space going home. Sunscreen alone would probably cost you $30.