I just encountered a massive convoy during my first patrol. I was ordered to patrol in front of Cam Ran Bay. Decided to get close to the mouth of the bay to see if I could find any shipping.
The crew calls out that they've spotted a ship. I look and in the far distance is a minelayer. I decide to go to periscope depth and pick up a several merchants.
Then I make my first mistake. I turn on TC

to 8. When I think the ships are in a good position I drop down to one.
I fail to notice that there are at least 15 contacts. And I'm being pinged by Destroyers. They don't seem to know where I am though.
I raise the periscope and see a Merchant in perfect alignment for a torpedo attack. I lock on(yes I still use Auto TDC).
And this is where I make my second mistake. I open the torpedo doors and hit space for each bay(thinking of GWX where Space fires) and then crash dive.
Realizing what mistake I go back to periscope depth from 80ft. By the time I get back up the ship is too far ahead, and the destroyers are closing in.
I lock onto a cruiser in the distance, and fire all four torpedoes. Crash dive and make a 180 to head out to deeper seas. Spend the next hour hiding from three destroyers. The torpedoes I had launched end up missing
Luckily their attacks were always off.
Feeling like a nub for botching that up and wasting 4 torpedoes, only have 8 left, I'm still in the area hoping something else will come through.
As a good portion of the crew is fatigued I'm going to chill out for the next two days and hopefully will catch a task force coming out of Cam Ran on December 14th.
Edit: scratch that I was heading out and ran into another task force also heading into Cam Ran. One of the destroyers saw me before I could go to periscope depth. slunk along and got into a good position, came up and launched 4 torpedoes at at a Heavy Crusier. Two missed, one hit and the back of the ship is almost underwater but I don't think it's going to sink. The final torpedo malfunctioned and ended up running in circles. Currently sneaking away from destroyers.