I have two of the v neck short sleeved lightweight tees and wear them a lot. They are thin so I do wear a cami under them except when it's really hot so if that bothers you maybe look at something else (but then I wear a cami under everything except when it's really hot so maybe I'm just weird)
The lemon yellow one from s/s13 faded with washing but I wore it loads so can't really complain. The pale pink one from s/s14 has been worn a handful of times and washed up fine. But as Spring said, they are very thin.
Can't comment on the actual boatneck part I'm afraid.