You can also spot one of the lights from the Officer's Quarters rise a bit too, but the crow's nest is the easiest part of the ship to see when the slight bob up occurs.I tried very hard to see if I could make out this detail but not sure if I saw anything. Perhaps a very slight rise of the mast but I might have imagined it. Perhaps my 65 year-old sight is not sharp enough.
Update: I went back and tried again and yes, I spotted the momentary rise of just the top of the crow's nest. To be able to spot that movement, one needs to keep looking at the nest as it submerges.