I think much of this has to do with how the person otherwise presents himself/herself. I agree with David B's analysis of the situation, but I know that tatoos have risen in popularity recently in all strata of society, so they no longer mean "trash" or "biker" or anything like that. (In fact, "biker" doesn't even mean "biker" anymore. My family doctor who is a neighbor rides a Harley, and a more "conservative" man you'll never meet!) I know that we usually cruise Radisson which is a pretty upscale line, and I've noticed fellow guests with tatoos before and thought nothing of it. Of course, if somebody was onboard with tatoos AND full "goth" outfit (for example) it would stand out and be just a BIT out of place!
Hope this helps,