Navtec backstay tensioner - how to remove pin?

[dunedin]

When removing the rig, how do you disconnect the backstay from the Navtec tensioner? The pin is different from anything I have seen before (see photo).
Seems to be the same on both sides.

 

[knuterikt]

Spiral retaining ring, doc here http://nebula.wsimg.com/e4d13a27772...2389BA50506216F6E&disposition=0&alloworigin=1

 

[dunedin]

Spiral retaining ring, doc here http://nebula.wsimg.com/e4d13a27772...2389BA50506216F6E&disposition=0&alloworigin=1

Thanks very much - hadn't come across this type of thing before.
And this site also shows more clearly the type of ring http://www.smalley.com/retaining-rings/removal

Something tells me that trying to remove a small springy clip one metre up off the stern of a boat is very likely to be followed by a splash and a need to find a replacement ;-)