Yep, I dress my boat. Do it for holidays, special events and just cause I like to. Tacky? It's your opinion (and I respect that), but I have to wonder why you make a value judgement about someone else's style. I prefer to think that it adds to the color of the day. Also it does have a rich nautical precedent. I just spent a few minutes looking up "dress ship" on the internet. I particularly liked the Google images (on both military and recreational boats). Also the US Power Squadron has a nice bit that explains the etiquette.