According to David Abel in the Boston Globe that mysterious "tracking ship" tied up on the Black Falcon is the "BEM Monge", a French telemetry ship that has tied up looking for some R & R.
I got those sailors in civies right, but my tin ear for languages ran true, I thought they were Russian.
The above linked article sez the French sailors on liberty are given $290 and the night off to explore Boston. Fair enough, I hope they enjoy themselves, but as soon as those poor boulevardiers taste what passes for domestic wine here in the USA they'll haul up the anchor and make flank speed back to Calais.