What are people doing with Mariner's compass? Is it anything but a sideboard card? Not seeing much reason to play this over other location control unless the leadership is what makes it somewhat relevant. I've never played with it. Any interesting interactions?
Mariner's compass
My personal view: garbage cards. I will never use it.
But it is not everybody view. You can see some other opinion here: http://ringsdb.com/find?q=mariner+compas
They are mostly talking about specific deckbuild against some scenario, which I never do, but I understand the point.
There is even a One deck who win every quest in the game ^^
Some quests have super nasty locations, this card can save you a lot of pain.
I find that it's a fairly useful sideboard card in Dale decks because you have so many allies who want item attachments, and particularly the spirit ally that does not exhaust to quest can be fairly handy with this to get rid of problematic locations in the staging area. It is quest specific, but can have its uses. It's not the best solution to locations, but it can complement other solutions. Certainly not a power card that finds its way into decks without specific reasons in mind.
I like the idea of this in a Dale deck, at least against certain quests. Here's the sideboard-ish conditions where you might want to use it:
1) Obnoxious in-staging conditions you want to put off for a while. For example, if you have East Bight and the Brown Lands in staging, you can swap out East Bight so that you can travel to Brown Lands. (Even better -- swap out a lone East Bight *for* a Brown Lands so you can travel to it...)
2) Want to find specific locations that advance the quest. Want the encounter deck to pop out Bee Pastures in CatC? Go and get it. Want Forest Grove to find Athelas? Go and get it.
3) Quests with locations that have "When revealed" effects, or quests that have surging locations. If you're ready to travel in Steward's Fear, there's a good chance you'd rather be travelling to a City Street in the deck instead.
4) Quests were something is affecting the location. Time counters winding down in Ringmaker? Swap it out. Lots of damage accumulating on locations you can "lose" in assorted quests? Swap it out for a healthy location.
It's definitely a sideboard card, but there are a lot of quests where it's handy to put on a North Realm Lookout.
As @Jban's recent take on the One Deck challenge (http://ringsdb.com/decklist/view/9896/one-deck-to-rule-them-all-1.0) points out, it can be useful to deal with locations Guarding objectives. Some of these become Immune, but if you're using player Guarded cards, the Compass has that niche in addition to its general usefulness.
Hmmm interesting, so you would shuffle the location in and the guarded item would now be free to take? Lost in Mirkwood definitely makes them immune, but that is an interesting concept of it checks out....