You may have bottled water with you on stage, but you should not drink alcohol or smoke on stage at all, as you're representing everyone onboard. You may smoke in your lounge in designated areas, and you may drink before, during and after your sets (within reason) IF ALLOWED ACCORDING TO SHIPBOARD RULES. Always ask for a glass when ordering drinks - do not drink out of beer bottles or cans. Also, as a courtesy to guests, do not sit at or crowd the bar - find a table.