galley sink does not drain
any tips on how to safely unclog

Take a first look at your through hull fitting and make sure it is not built up with growth. If that is clear, then I would try a wire plumbers snake and run it into the drain hose after removing it from under the sink.
Hayden

love the site come to it often
and thanks for your answer

In addition to the steps Hayden outlined... don't forget to look at the obvious..ie is the drain strainer/stopper in the drain? if so remove it..