I'm just off of Serenade, this morning. All staterooms are/were equipped with 2 RCL logo white face masks (not N95). I wandered about the ship, used the elevator, ate in the Windjammer, used tenders, etc. I always wore a mask when around other passengers. One man, the same man, twice belittled me for wearing a mask (two days apart). The second time I told him to shut up and mind his own business, and if the did that again I'd file a complaint against him with guest services. Yesterday and this morning, there was a lot of coughing and when people coughed few covered their mouths, from what I observed. I witnessed few crew members wearing a mask.