I started thinking about this topic last week while fishing with Jackmack. He had just tied up a new pattern that looked like it would sink well, but that seemed to suspend more than it sank. With the heat driving fish deeper, I'd like to have a discussion on why flies sink. Weight is an obvious answer, but I'd like to hear what your theories are on other factors that affect not only that flies sink, but on how fast they fall.

I have a good grasp on the overall bulkiness of a fly or streamer and how its density versus its bulk determine how fast it sinks, but what other factors should we think about when designing and tying a fly we want to get deep quickly?

Also, what materials lend themselves to a fly or streamer designed to get deep? What materials have you tried that disappointed you with regard to getting deep?

Runing lines and shooting heads for me ...
Intermediate
Class III
class VI
LC-13 fast sink

some materials (deerhair comes to mind) are more buoyant than others, but weight, whether its just the hook or added weight is the only thing that can make a fly sink. I have some sink tip line & I dont really like it much but it does cause the fly to sink well. I'm gonna go ahead and say that for me, when fish are deeper than 5 or 6 feet, I would rather use conventional gear...but I'm of the opinion thats there is more to fishing than the "fly" part, although thats my favorite part, but hey catching is catching.

George, you're cheating on me.

I should clarify and say that I'm thinking more about fly design and construction than about a type of flyline or just adding weight.

interesting thing that has nothing much to do with fly fishing, the popular "Senko" and its clones used for bass fishing are known for their sink rates achieved without added weight, the difference between them & other soft plastic baits is that Senko's are loaded with lots of Salt, lots of people are of the opinion that salt makes the fish hold onto the bait longer but its main purpose is adding weight.

Thats funny cause salt is more boyant than water.

LOL - then I'll second BAB's comments and go with th devil's conventional gear with lead head bucktail jigs or crankbaits...

Well then let me put it another way. If we wanted something castable that would get us as deep as possible on floating fly line for 'gills and bass, what materials should we think of working with, and what materials should we stay clear of?

Guess I would have to do some experimenting by dunkin' materials and pool testing flies - aint gonna cause I know what works for me...

Bucktail/deer hair hollow floats.
Icelandic wool absorbs water and sinks.
Feathers soak up water so maybe neutral .. .?
Shynthetics - it all depends ...

'Ya not gonna let me use lead wire or heavy hooks ???

1st would to be use a fluorocarbon leader/tippet(fluorocarbon sinks, mono. floats) . Next on to materials; heavy wire hook,lead/bead chain eyes. Tie as sparse a fly as you can. Bulk on a fly will slow or stop the sinking action. Bucktail sinks just fine once wet. Deer body hair is hollow because it is used for insulation so avoid it. Also avoid most synthetics as that are petroleum based thus they float. Feathers will slow the sink rate because the will add bulk. Wool will sink,but you have to get it wet all the way through. Use unwaxed natural fiber thread(wax will float). This will shorten the life of a fly but do not use a head cement. Now if you find some that once a drop is dry and placed in water and sinks please let me know because I will switch to it ASAP. I hate you for this question! I must now pull all my stuff out a play with it to see what will float and what will not EDIT- I know this is not a complete list so further help is required! "Other than weight,why do flies sink?" It has nothing to do with weight, but with density(specific gravity). If an object has a greater density than fresh water it will sink in fresh water. BTW just because your fly sinks in freshwater does not mean it will sink in saltwater. Saltwater has a higher density and takes more effort to sink in.

so your saying that density makes things sink?

gravity sucks

Yes when the density is less than that of water it floats, and vise-versa.

Now we're talking. I think specific gravity is the term we're looking for here. It works especially well for us because specific gravity is the density of something compared to the density of water.

Which is why I used both terms. It has been my experience in the past when the term "specific gravity" is used I get blank stares,but when "density" is used everyone nods their head with understanding. I guess I could have tossed in total mass vs gravity, but was not sure if that would muddy the waters more or not. Sorry I should have known that this group is above the avg. I.Q. I deal with daily. I am a product of Texas public schools that teach to the lowest common denominator in the class room .