Ever pulled a Capt. Dodge?

I was just wondering if all of you experienced Kaulens ever pulled a Capt. Dodge (Down Periscope) and pulled in underneath a huge slow moving tanker to avoid detection?? And would this help avoid detection?? seeing as how some one listening would hear the tankers screws and ASDIC would probably also pick you up as part of the keel of the tanker?? And if anyone has done it Id like to know how you did it. Especially if it was with no external camera

Just a thought because I just read a post about some one sneaking into Gibraltor that way.

And while we're on this topic, what all interesting /wacky tactics have you all used before that have worked??