Were Allied submarines operating in the Atlantic during WW2?

I've read my share of uboat books but rarely do I hear of allied subs during the battle of the Atlantic. I assume it would be incredibly dangerous and prone to friendly fire incidents since aircraft and ships probably wouldn't wait for identification before firing https://speedtest.vet/ https://vidmate.bid/ . I can recall the royal navy having some in the Mediterranean and one random uboat encounter where the captain swore an allied sub tried to surface ram him. So were there patrols out and how did they avoid friendly fire incidents?

 

...you don't hear much of them, do you? but like this article states, a lot of the action was North Africa and the Med in the beginning.....after that, there wasn't much action in the Atlantic--especially compared to the Pacific
..Germany wasn't the one who needed to use fleets to cross the Atlantic
The Surprising Submarine Squad That Patrolled the North Atlantic