> Wouldn't it be enough to send some small thing connected by thin wires or wirelessly to the submarine (lasers, ultrasound, whatever) that could aquire locatio

> Wouldn't it be enough to send some small thing connected by thin wires or wirelessly to the submarine (lasers, ultrasound, whatever) that could aquire location and communicate it? They do, using either tethered buoys or 'buoyant cable antennas' (the cable is the antenna and is itself buoyant) They can use these without coming to periscope depth, or even slowing down.