The wreck is a fixed location as far as I know, I used to run past it on a regular basis until I needed to find it then I couldn't find it for over an hour. (was quite frustrating draining several batteries in my search). There is already a thread about this that should narrow down the search area.
As for the blueprints... I don't know why but I have the worst luck finding the workbench, moon pool and the nuke.
I have spent several power cells exploring the deep grand reef without finding useful fragments.
I often have the Cyclops long before I find a workbench or moon pool.
Check the wiki, there should be a map or at least directions to various areas that can help.
Comments
As for the blueprints... I don't know why but I have the worst luck finding the workbench, moon pool and the nuke.
I have spent several power cells exploring the deep grand reef without finding useful fragments.
I often have the Cyclops long before I find a workbench or moon pool.
Check the wiki, there should be a map or at least directions to various areas that can help.