The ArriveCan app is definitely required even if not leaving the ship. With all of the covid protocols changing daily I can't definitely say the covid test will be required but I would hazard to guess the answer is yes for awhile at least. If he doesn't believe you he can google "do I need to have arrivecan if I'm not getting off the cruise ship"....the answer instantly pops up 😄 .
Recently travelled with two 14 yr old girls, a 16 yr old boy and 19 yr old. We were on the Bliss but also had the go cart race track, etc....based on our experience the Encore would win hands down...they were on the cars most of the time 😄