Do the Rooskies make a habit of using 80 meters in USB mode? Seems like it’s pretty common for marine purposes (military and otherwise).
I’ve read numerous reports from hams in Europe of Irish fishing fleets, Finnish trawlers, Italian fishermen in the Med, etc. using 3500-4000 kHz in USB mode for ship to ship comms. It’s a good place to hide a military net. Same with 40 meters.
The split frequency operation seems pretty common too.
Rooskii militaryskii makes use of upper and lower sidebandskiis, one of the few military that does upper and lower. Not only do they often encroach the HAM bands with their nefarious ways, they also employ calls that are obviously US HAM calls in cw mode, such as N9KT and similar.
That said, these aren't naval calls for all I know, more like army, air defense, air force, or strategic rocket forces.
They also have no problem firing up cluster beacons in the HAM bands as well as gigantor radars.
"Cluster Beacons
A group of radio beacons with single-letter identifiers ("C", "D", "M", "S", "P", "A", "M" and "K") have been regularly reported near 3594, 4558, 5154, 7039, 8495, 10872, 13528, 16332 and 20048 kHz. The term "cluster beacons" is frequently used for them, as they transmit in parallel on frequencies only 0.1 kHz apart. These beacons transmit only their single-letter identifier in standard CW (A1A) using Morse code"
https://www.sigidwiki.com/wiki/Morse_Code_(CW)#Cluster_Beaconshttps://www.smeter.net/propagation/beacons/7039.3-k-petropavlovsk-kamchatskiy.phphttps://www.sigidwiki.com/wiki/29B6_%27Kontayner%27_OTH_Radar