Thanks for the info! We will probably ask to move to the sea terrace cabin.
To me using the balcony consists of looking out onto the water, port, etc so if I can’t see while sitting then I essentially can’t use the balcony. I definitely didn’t realize it was important to me until I saw what it looked like. That’s probably also because I didn’t know it was a thing but I’m glad to have the chance to sort it out before boarding!