Hello Tony
The WW I subs did have radio which enabled them to transmit and receive Morse code using radio waves. This type of radio was also in common use during WW II. It was sometimes called "wireless telegraphy". The type of radio of which you are perhaps more familiar came a little after "wireless telegraphy" and was called "radio telephone". Radio telephone enabled people to talk back and forth just like using the regular telephone but using radio waves in place of telephone wires.

If you are able to download pictures attached to an e-mail, I will send you a neat picture of the US Navy's first submarine which came into the fleet in 1900. It is a Holland boat and the hull looks remarkably like the hull of a nuclear sub today but of course much smaller in size. It could make 7 kts. on the surface and 6 kts. submerged.

Let me know if you would like me to send the the picture.

Don B