I use leader link on 5 wt and below. They must be checked before each day
of fishing as cracks can develop from getting smacked on rocks on the
backcast (or so I've heard). They DO NOT float. Unless you have a very
good, well sealed fly line, they will bring the tip of the line down.
As I said, I do use them on 5 and below. I'm concerned about their strength
on serious fish (snook, bones, baby tarpon, stripers). Also, remember to
use the appropriate size for the line, or they may hang in the tip top.
To seal my fly line, I put a dab of flexament or wader seal on the end of
the line after its been out of the water in a dry place for a couple of
weeks. I always replace my leader links at the start of the season and use
the flexament on the line at that time.

--
Frank Reid
Euthanize to respond