fly line depth??

[FISH11]

Fly line is just referring to the Mac swimming without weight, usually behind while you troll or drift and it decides how deep to swim. Usually that will vary with the type and size of Mac you use and whether you are over structure. Usually I control how much line I give it by the depth of the water I am fishing and whether there is structure like heavy kelp. Not more than the depth and less if over heavy kelp otherwise it will tangle you up in a hurry.