On the Caribbean Princess there is a small standing smoking area on deck 7 starboard aft where the promenade walkway narrows to go around the stern of the ship and where there is a cigarette disposal unit attached to the wall. It's only at this small area, not the entire starboard side of the promenade deck.
Can I bring edibles on a Princess Cruise?
Medical marijuana is not allowed on cruise ships, even if you have a prescription for it. This includes pot, edibles and cartridges.