Very weak signals...at first I thought these guys were on 7707 kHz USB, but nope, 7706.6 kHz USB. That does track though, since most HF SSB marine radios show frequency in kHz notation with one decimal point (for example, 2182 kHz is displayed as 2182.0 or 2.182.0 - so 7706.6 would be shown just like that, or as 7.706.6 on the radio's frequency display.
Received via G8JNJ SDR receiver located in the South West UK.
7.706.6 MHz USB
7706.6 kHz LSB