When the French Navy comms centre gets traffic the 4285 sig will drop, then restart into a response to the calling ship in the clear that repeats a few times with items like number of messages received, number of messages remaining to be sent to the calling ship, etc, then any further response if needed, then back to the channel marker text.
Typically, ships will call on predesignated qrgs often located a few kc up or down from the 4285 sig, initiated by the ship via ale or 4285, so look for those in the waterfall. Some qrgs will be encrypted fleet broadcasts that simply carry whatever the days broadcast is, with no traffic handling on that channel, other qrgs such as this one handle ship/shore traffic exclusively. Most NATO navies operate in a similar manner as far as 4285 goes.
Halifax, for example, used to send its listening qrgs in the clear in the 4285 channel marker.
10,943KHz S4285 75bps Long
[2016-09-21 17:32:52] NAWS DE CFH ZKR F1 2822 3394 4158 6242 8324 12371 16552 AR