Hi Mark -
The enclosure is so obviously the way to keep away from hardware encryption cobblers, that yes, it is definitely the way to do this. 
However, I am just recovering from two months on Tramadol, :o and the back injury which this narcotic was prescribed for, so I my head is very much still “out there, man” ! (hence the PnP requirement!!)
The associated work backlog is a bit of a pain, and then there’s… blah blah blah - you get the idea.
The “local” “shops” only seem to have stuff with hardware encryption in ( I.E. Pcworld sell dynamode enclosures ) and Maplin only seem to have either USB 2 ATA only enclosures, ( and no large disks ??? ), or USB 3 SATA raid enclosures ( for £115!! exc disk(s)). As I said above, it appears that I need to “make some time”, and order the stuff of this interwebby thing, but that is just something else to do!!
I probably asked the wrong question really - perhaps I should have said:-
“Who has recently bought an external HDD which worked with Ubuntu 12, out of the box, PnP, and which one did you buy, please. Thankyou”
Now, given that Mrs Sim works for JL, and is there today (!), then if I/we knew Brand X works, and JL sell it, then… job done.
Sorry if I have confused all this into a heap
We will go and have a looksee on the morrow…
Thanks
ATB
Sim, originally from Earth, and returning slowly ;D