A Dover Cache Convergence is Happening!
(Someone let me know I was making these too easy and they wanted them a little more challenging to solve. Ok, I can do that!)
Being a mystery, the cache is not at the posted coords.
No need to go there, all you need is provided on this cache page.
To find the final cache location, it is:
2051.993 metres from a cutter
1718.925 metres from a grapnel
2957.556 metres from some fake ice
That should give you more than enough information to find this hide.
Have fun! Oh and bring you own pen!