Submarine wreck tours - Divernet Magazine

Divernet magazine is the online version of Diver magazine and they have some great material.  My favorites are the Wreck Tours and there are currently 79 of them!  Each tour is a page or two of text and illustrations describing a wreck and a dive on it.  I really appreciate the hand drawings of the wrecks.  They do a good job of showing the overall layout of the wreck - much more than a photo or two can do in most water. 

Here are links to the two sub wrecks that they describe:
UC-70

HMS Umpire

And check out the whole list:
Divernet Wreck Tours