a term are
just that -
silly rules.
Getting the meaning right is the priority number one, two and three - "niceties" of style? like not repeating a term? Distort the meaning to accommodate that kind or rules? Not in my rule-book, and I for sure wouldn't want anywhere near me someone who would translate a contract (or any document requesting precision) for me following THAT kind of priorities ...
As for this text:
you can find what are "navires côtiers" (defined by opposition to "de haute-mer") but not much about a subcategory that would be called "navires côtiers de façade" just about 10 ghits ...Could it simply be
all the "navires côtiers" operating along a given "façade"?
BTW "façade" covers quite a lot, you can find samples of "façade méditerranéenne" / "façade atlantique" / "façade Nord Atlantique" ...
http://www.cnrs.fr/CNRS-Hebdo/bretagne-paysdeloire/actus.php...and variations - CNRS seem to be the only ones using the term "navires côtiers de façade"