my apologies orkney tuning is slightly different it is cgdgcd.
" ORKNEY TUNING

The Orkney tuning (CGDGCD) has become my favorite over the years. It is a wonderful tool for melodic (non-linear) playing, in which you avoid playing subsequent notes on the same string. This technique (Pierre Bensusan calls it "harp style,") allows for a very smooth and gentle delivery of the melody and avoids the staccato effect that marks many guitar arrangements of fiddle tunes.

The Orkney tuning is also a great tuning for session back-up. I like it better than DADGAD. You get one extra note's range in the first position and when you're in C, (which in Orkney is often,) you've got a fifth in easy reach at the fifth fret of the first string. This allows for a nice ringy sound. In DADGAD you'd have to stretch your pinkie to the 7th fret to get the equivalent effect.

Drawbacks are that the 6th string tuned down to a C note can sometimes become a bit spaghetti-like and hard to tune. I find, however, that using a heavy 6th string makes this problem quite manageable. Another possible drawback is that playing in D or A is best done with a capo at the 2nd fret. Some people prefer an, un-capoed sound. On the other hand, you may like the higher, ringy sound of the second fret D and A chords.

In al, it's a great tuning. In fact, may theory is that the only thing keeping CGDGCD from overtaking DADGAD as the session player's tuning of choice is that its name has heretofore been impossible to pronounce. Accordingly, I hereby christen it "ORKNEY" to sharpen its competitive edge. Try it out and let me know what you think."