My friends just finished a cruise on the Baltic on Marina with 700 on board.
We have cruised on her many times. I believe the pool opens at 7 am, a smaller pool but not busy in the early morning.
Afternoon tea is at 4 pm.
Terrace & Waves I believe is 8 am.
Waves is great if you get back from shore tour too late for Terrace lunch as it is open later. Try the Surf & Turf sandwich of Lobster & filet mignon my favourite with only half of the bun. The ice cream station is also out at Waves open till 4pm.
Enjoy!