The only problem I see with the keychain type is being able to get it available to be tapped by waiter when ordering and the security officer when getting off and on the ship. The wrist band will be better. I purchased the Princess clip and put it either on bra/bathing suit strap or collar of shirt so it was very easy to unclip when needed and also at the right height on body to unlock the door. When worn too low, like pants pocket, it dose not unlock the door as you approach the door unless you take it out and bring to chest level.
