To the stars through/from water, it's a play on the phrase ad astra per aspera which means to the stars through (or in the context despite) hardship.
The original phrase also is fitting but since the water in this case is their hardship I think is what makes it a pun.
I've talked myself into thinking it's actually a pun. Ad astra per aspera is a set phrase in English, so any modification to it is punning the phrase. In this formulation, aquam still carries the original meaning of ardua, hardship. While this wouldn't be a pun to a native Latin speaker, I haven't met too many of them.
I kind of wish my work had mission patches like this, though "Deployed Client X" doesn't sound so dramatic.
