Tip for trolling subsurface:
Run a medium planer off stern cleat.
Have multiple very large snap swivels and fat rubber bands
Let line out to desired distance
Attach line to non snap end of swivel by tying with rubber band
Clip snap to planer line and drop back
After fish catch, rig next snap swivel...no need to pull planer in (till you run out of swivels)
Saves fighting fish with heavy trolling sinker and easier to switch baits/ lures.
Drawback is another thing for fish to wrap around.
Fair winds and tight lines