Depth Meters and Compasses

[Dr.Love]

So as many of you probably know if you've played the 1.3 update, making a cell phone requires a GPS, and to aquire one, you need a watch, a depth meter, and a compass. I've been trying to farm mimics to get compass, and the same with giant bats for depth meters, but no luck.
Does anyone have a spare of either one of these for trade or any tips for farming these?

[Diesel]

I am trying to get that fish finder, the ♥♥♥♥♥♥♥ angler wont give the fish calneder thing. I have already gotten a golden rod ffs

[Cronus]

If you have the statues and wiring, you could set a Bat and Piranha statue up in a small box with lava and/or traps, and hook them up to timers so that they die shortly after spawning, then it's just a matter of waiting until the items drop (BTW, Piranhas are able to drop the Compass as of 1.3, and Mimics spawned from statues won't drop any items according to the wiki)