I don't know how many times this subject has come up but mis-information abounds when discussing standard WF and DT lines. THERE IS NO DIFFERENCE IN THE FRONT TAPER OF A DT AND THE CORRESPONDING WF FLY LINE.
They are identical for the first 30 feet in mass and mass distribution. THEREFORE, FOR THE FIRST 30 FEET, THEY CAST AND MEND IDENTICALLY.
It is after the first 30 feet that differences can occur. If you only fish short casts, get a DT. If you roll cast often get a DT. If you need to shoot long casts, get a WF.
Read what Bruce Richards has to say about DT vs WF lines:
"Almost all WF lines have heads that are 35-40 feet long. Add a 9-foot leader and the distance to the fly from the end of the head is 44- to 49-feet. Up to this distance when both DT and WF lines control and roll cast the same. There are not many typical trout fishing situations that require longer casts. What this all means is that DT and WF lines work pretty much the same at the distances we fish most often."
"Everybody knows that WF lines are better for distance than DT lines, but is that really true? Well, yes, but the difference isn't as big as you might think. Because of their small, light running lines, WF lines shoot better. But remember, this benefit starts at 44- to 49-feet when the running line is in the rod. If your fishing situation calls for many long casts, it is certainly a little easier to do with a WF line but don't think that DT lines won't shoot. They will, just not as far."
- Double Taper Versus Weight Forward: Which is Really Better? Fly Fishing Information Center
The VP for Orvis in charge of fly lines says the same thing in a podcast.
Orvis and Cortland used to publish their tapers. Orvis still does but Cortland does not. I compared them and the front tapers were identical for comparable fly lines. It is really not fair to compare bass tapered WF's with regular DT's and say the tapers are different. In every instance in which I was able to obtain a chart of DTs and WF's of identical fly line series such as the Cortland 444SL lines, the front tapers of both DT and WFs have been identical.
However the WF has a rear taper that leads to the running line and the lines differ in this regard. I believe that the lines are identical until the rear taper begins. If you will look at the Orvis chart below, and compare the two charts for the Wonderline Generation 3 Trout Fly Line in WF and DT you can confirm what I have said. For example the 5 wt of both fly lines have a tip length of 6" and a front taper of 66". Add the distance until the rear taper begins and the lines are identical for the first 37 ft. That is why Bruce Richards says they cast the same. To say that DT's cast better on shorter casts is simply not possible unless we are talking about two different types of fly lines like a regular DT vs a bass taper WF line.
Orvis makes an easy mending WF line that is longer headed WF that the Orvis says combines the best of Dt and WF's but that also is not an apples to apples comparison.
Fly Line Taper Charts | Reference ? Orvis Fly Fishing
If anyone can find an online comparison of tapers from the major companies of identical series of fly lines in DT and WF that show a difference in the front taper, I would appreciate the URL.
Since lower weight lines are more often used on small streams, I buy DT lines for 4 wt and below, and WF for 5 wt and above. It is less likely that I will be need long casts when fishing these lower weight lines and more likely for higher weight lines. Lower weight lines are also for smaller flies. Depending on how you use your fly lines, you may still want to use a WF for 4 wt lines and the DT lines for 3 wt and below.
I suggest you adopt this method and decide when you want to make the change from DT to WF. The reason to use a DT rather than a WF is that DT lines have two presentation ends and they will last twice as long. It is a money saving method.
Before WF lines were invented we used to make our own. I still make my own "hybrid WF" fly lines as follows:
For 4 wt line and below, I use DT lines by cutting the line in half. Then I add running line
to the the cut end of the DT with a loop to loop connection made by whip finishing the the fly line core into a loop. When I wear the first line, I swap it out for the other half. It is how we used to make our own WF and shooting heads.
The spare half a fly line stored in a cool dry place on the original spool will last longer than putting the whole line on the reel. There is an extra expense because you need to buy a spool of running line, but I have used the same running line for 25 years. The running line is actually a thin level fly line exactly like the running line of a WF line
, so it shoots just like a commercial WF line. The running line comes in several diameters. For the 4 wt buy the thinnest .027".
Using this hybrid line, you can shoot it just like a WF. With the "head" of the fly line being half if a DT at about 45 Ft, it will act like a DT for the first 45 feet including the ability to roll cast.