fritz -

My impression is that the weight of a piece of fluoro is determined only by its length and diameter. A longer, thicker piece will weigh more than a shorter, thinner piece, but both will only weigh a bit more than the amount of water that they displace. While a thicker piece will be "heavier" it won't necessarily sink faster, and the thicker it is, the more surface it has may in fact cause it to sink slower because of the resistance of the water against its surface. It seeems that most folks who use fluoro for nymphing suggest using smaller ( thinner ) fluoro so it will sink faster.

Poly leaders incorporate tungsten, and the sink rate is determined by the amount of tungsten as a proportion of the overall leader. Sink rates typically run from about an inch or inch and a half per second through about seven inches per second, with interval sink rates stepping up about an inch per second from the lower end. It is the amount of tungsten, which is clearly much heavier than fluoro, that is the key to poly leaders getting streamers ( and anything else ) down faster.

As to the expense, if you put a tippet ring or small swivel at the tip end of the poly leader, you only have to change out tippet as necessary and the leader itself will last for quite some time. Probably well worth the expense if you like using the same floating line for a variety of fishing approaches.


P.S. I personally prefer a full sinking line for fishing streamers. But some folks prefer floating lines because picking them up and casting them is easier for them, and that seems particulary true for people fishing from drift boats and rafts.