Labor intensive..? Ok the man will sweat a little, but he could save himself a few dollars if he were to do some of the prep work.
I understand not everyone is handy. And not everyone knows how to lay carpet. But its not a impossible job either. The trick with with gluing anything down is patients. Once prep'd you only do a section at a time, you glue both surfaces and allow the glue to become very tacky and then put it in place. So no its not a impossible job, but then sometimes its worth letting someone else seat and get aggravated too.
This isn't a boat deck but its some of my work redoing the headliner of my semi truck sleeper. The principle is the same though