typically the differentiators are

1. long endurance / loitering

2. remote control / streams

For underwater drone vs torpedo, agility and propulsion method, torpedoes are typically built for speed and don't need the same turning radius

The spectrum is becoming increasingly gray as the variety of unmanned / projectiles increases. You can see the same thing in UAVs vs missiles. Apparently Ruzzia is now putting a2a missiles on their Shahad drones, what even is that now... a missile with self-defense missiles?

I haven’t seen much of the “Sub Sea Baby” drones as they call them here but the regular sea baby’s are more like boats. They move across the surface. They are remotely controlled. They have weapons besides kamikaze attacks. I would guess this is the same thing.

I don’t think they are getting “launched” and reliant on maintaining that initial velocity like one imagined torpedos either.