Ken S wrote:slime line?
the old-fashioned name for intermediate or neutral-density sinking line - you can see one on my reel in the first photo.
They cast farther than a floating line because they're smaller diameter, slice the wind better, sink at a very controlled rate for counting down, eliminate the need to use weighted flies, and eliminate hinge and weighted fly yo-yo. They fish the Zone kinda like a TSL grasswalker.
They basically disappear in the water, and fish great with 5' leaders.
I fish them in the salt anytime I don't need a floating line (shallow grass) or a really fast sinking like a Teeny TS shooting head (jetties, offshore, ripping current in a tide pass). Slime lines are especially good for dock and canal fishing. I go to slime line most often in the bays, and it's also go-to line for the surf.
here's a rat red on LHL, wading at the first duck blind, and fishing into a mid-thigh-deep hole. Had pretty good fish sign in jumping small bait, caught this rat and a good ladyfish, but I think you can see the transparent fly line in the photo. I have 3 of these, one from SA Mastery (bonefish intermediate) and two Airflo ridgelines. Two are monocore, and one of the Airflo is coreless, transparent, and really thin
both fish are on my kicking shrimp, which will also work for change-up for dock fishing, but a bit more complicated to tie