AWOL:
I remember reading a defence paper about a proposal to use green lasers to transmit data to submarines at higher datarates than the ULF systems normally used.
The devices in question were mounted on satellites, which may limit their practicality for amateur use, but the principle remains.
How would the satellite laser know the exact location to point the beam to a submerged sub? Doesn't sound like a practical method to replace the ULF system that allows the sub's location at any time to remain secret even to our side but still able to receive launch instructions.