Yup. It's got rubber gaskets at the wrists, ankles and neck. Inside, it's perfectly dry.
James Bond wore a tuxedo under a drysuit.
Goto 4:28
The Myth Busters confirmed that it worked. (although, a few wrinkles needed to be ironed out)
A scuba diver can wear a tuxedo underneath his drysuit, go underwater, resurface, strip off his scuba gear, and be able to present the tuxedo perfectly. (This was inspired by the pre-title sequence of Goldfinger.)
https://en.wikipedia.org/wiki/MythBusters_(2010_season)#Episode_153_–_"Mini_Myth_Madness"
You know, I remember seeing that and wondering if it would actually work!! Ha, amazing!!!