Regulations? Individual operator OpSpecs would probably cover this and in the case of the N. Atlantic, the MNPS manual strongly recommends this. Only a fool would operate on the N. Atlantic tracks without benefit of a plotting chart. Simply to many variables that one might encounter where the plotting chart would bcome the tool of last resort. If your thinking about skipping this little detail please do all of the other operators a favor and let them know when your in the same airspace.
There are exceptions to all the rules and one that comes to mind is west coast of the US to PHNL. There are established fixed tracks beteen these points so you are basically flying an airway which is in your NDB. In this case I have know the FAA to give the operator a pass on plotting but they still need the plotting chart onboard in the event of a reroute. There are also fixed airways in the No Pac but I believe that most if not all operators are still using plotting charts or at a minimum have them available should the need arise. An amended clearance involving a random reroute would be an excellent example.
Not sure what is driving your original question but accepted standards require a degree of compliance with best operating practices. Not plotting, not carrying the correct charts, are but a few of the items that differeniate the pros from the problem children.
Sorry for the harsh words and perhaps I simply read something into your question that did not exist in the first place.