You're mixing up a few terms, there. Most TT's come from the mfg. with either vinyl sheet flooring or carpet. The vinyl sheet can be overlaid with engineered wood plank, a composite of wood veneer glued to a substrate of various wood products or vinyl laminated plank, a composite of compressed wood fiber with a vinyl wear layer on the finished surface. This can resemble wood grain and can even be embossed to represent wood surface imperfections. Either of these flooring products can also have a foam layer on the bottom which can eliminate the need for an underlayment material to be installed underneath the plank. There is also available complete vinyl plank (Allure, Dimensions, etc.) which is made totally of vinyl.
I'm of the same mind, as to water on the surface, I can actually take a shower or use the sink without a gallon of water dripped on the floor. Some folks are challenged by this, I assume.
When I installed vinyl laminate in my trailer, it came with foam backing but I chose to also install a tough underlayment. The price was not that much greater and I thought that the underlayment would keep moisture from reaching the plank from below and allow a better feel under foot. Results have been good.
