This is the type of thing you will have to work out yourself. I realize that the earlier Cruise Ships are different than our current C Dories. I have found sinks which are as small as 8" bowl type, or 5" x 8" rectangular type. and built small sinks using these in other boats. You first have to find the small sink--RV or boat catalogue--then build the cabinet--you may even want to taper the under the sink back to the wall--slanted in-just with plywood to cover the piping for the drain and the hot and cold water, thus allowing room for feet, knees etc. I have put these in the corner. The geometry is not easy, but using cardboard templetes allows a precise fit. Sorry I don't have a photo of one handy.