The hotel is made up of an underwater disc containing 22 bedrooms with sea views, connected by lift and stairs to a similar disc above the surface containing other hotel facilities, rather like a dumb bell. On arrival, guests will be given basic instructions on how to dive to a depth of about 10m (33ft), as that provides a good color environment in sunlight. Lower than this removes everything but blue.
Then, the guests can gaze outside at waving seaweed and relax while fish swim by. See more here.
The other difficulty is weighting boxes containing everything that needs to be placed in the rooms daily and lowering them underwater. Seems like an awful lot of bother. Why can't they build a shaft with pulleys, like the old-style dumb-waiter used in mansions when plenty of servants attended to every guest's wish?
So, those people who like a challenge can take a break at an underwater penthouse suite, rather than facing the blue grotto in Egypt's Red Sea, where more than a hundred testosterone-charged men and one woman have been lured to their death.
I won't be staying in an underwater apartment. It sounds way too expensive and risky.