Over-Lining a Fly Rod
Over-lining a fly rod is a very simple process that can be pretty helpful, but, surprisingly, many people have never tried it! Generally, when picking out a fly line size, you try to match the size of the fly line with fly rod size (i.e. 4 weight rod = 4 weight line, 6 weight rod = 6 weight line, etc.) Therefore, what “over-lining” means is using a fly line that is one or two sizes larger than your fly rod. For example, if you have a 3 weight rod to over-line you would put a size 4 or 5 weight line on it.
I have been playing around with over-lining rods for close to ten years now, and have found some of the good and the bad of practicing it. I’ve used this method primarily on very small to medium sized streams, so that’s what is focused on here.
Here’s what I’ve found:
1- Your rod will load more.
On an elementary level, fly lines are created to bend your fly rod. This bend is what creates the force/momentum needed to send your weightless fly across the pond. Think about it - if you tried to throw a sz. 20 Griffith’s Gnat you would be unable to throw it the length of a Honda Civic, but with a fly line, you can heave a fly 50 feet no problem. That's physics at work right there.
Weight is necessary to get your fly out to your desired distance. It's a game you play with each rod - how much to increase or decrease the weight to maximize your distance and ease of casting . Obviously, when you increase that weight, the fly rod will bend more. That would be the first benefit I see. After all, when you can feel the rod bend more, you will better understand how the casting motion needs to be timed.
This reveals why I almost always give an over-lined rod to a newbie or someone who has problems casting. Over-lining helps them feel the rod load and in turn know when to go from the back cast to the forward cast.
2- Your rod will load with less line out.
To me, this is the primary advantage. In small stream fishing, over-lining your rod can be an incredibly helpful tool, and is almost a necessity. Because the increased weight will make your rod bend more, you don’t need as much line to load the rod and shoot your fly out. This is incredibly helpful in small streams.
Here is one instance to prove it. When I am trying to make a short cast between 10 and 20 feet, not much of the fly line is out of the top guide. Because there is minimal line out, the rod will not load properly which in turn means my cast will not be accurate. When you are in the wilderness with millions of branches, trees, and rocks that are always willing to grab a fly, and you must hit a target the size of a dinner plate, it is incredibly important to be accurate.
Let's pick this apart in real-life numbers.
I have a 3 weight graphite rod I use on small bushy streams. With a 3 weight 100 grain fly line on it, I need close to 10 feet of fly line out of the top guide to make consistently accurate presentations. Add on a 7 foot leader, and the minimum accurate cast I can make is 17 foot. Doesn’t sound so bad until there’s a branch right behind you, and a pool teaming with fish 13 feet away. When I put on the 4 weight line, I can accurately present the fly with as little as 4 feet of line out. This means with a 7 foot leader, I can send a fly accurately 11 feet out. If I need to go shorter than that, I can just bow and arrow cast wherever need be.
3- Casting In Wind.
One cold December day several years back comes to mind often. My dad and I were on a local small stream, and the wind was fierce. We were using small 2 and 3 weight rods with tiny nymphs. We were trying to cast into small pods of fish we could see, but there were several difficulties as we faced low, clear water, spooky fish, and worst of all, wind.
We were casting from a distance so as not to spook the trout, and while the fly was in the air, the wind would blow it completely off track. What was the problem? Our lines were too light to effectively cast into the wind at the distance needed.
We caught a few fish that cold windy day, but not like we should have, AND I dropped all of my fly boxes in the river that day…
Another windy day a week later I took out the same 3 weight, but put on a 4 weight line to try it out. It was magical. The same gusts that sent my fly off track a week before didn’t seem to affect my fly nearly as much this time. Of course, there was still some play, but it was noticeably different. I also over-lined my dad’s two weight with the three weight line I was using the week before, and the same result occurred. Noticeably better casting in the stiff winds, even with small rods on small streams.
*Disclaimer* You may have heard people say in bad wind you must downsize your line, not over line your rod. From what I have read, seen, and practiced, this is sometimes effective advice, but applies with larger line sizes (say 8, 9, 10, etc. weight lines). This works because there is less surface area for the wind to grab hold of. Whereas with our small lines, they were so light they were being easily pushed around.
1 - Stealth
No way around this one, if you are putting on a larger size line, the increased weight will cause a bigger splat. Drop a small twig in a river and listen to the splash; then heave a big log, and there will be a big difference in sound.
On a microscopic scale this will be the case with varying fly line sizes. If you are throwing a 5 weight line you will cause more of a stir than with a 3 weight line. As well, when you go to pick your line up it will cause more of a sound. So when you over-line you have two bigger noises, 1) when the fly line splats on the water, and 2) when you go to pick the fly line off the water.
Now, you shouldn’t be casting your fly line on top of fish anyway, but I have seen brook trout spook from the subtlest of movements, and I am not too convinced a medium sounding splash wouldn’t spook at least some of them. Of course, you are already going to have some noise, but what we are concerned with is being as stealthy as possible, therefore over-lining a rod will create a sacrifice in stealth.
The increase of weight will impact the amount of drag your fly faces. The reason for this is when you have extra weight, your fly line will be more impacted by variances in current. Drag is one of the ultimate enemies to fly fishermen because of its detrimental effects to your presentation. This being said, over-lining your rod is not as helpful when you are trying to make long drifts because the drag will be multiplied, and more affected by the current, which will then translate to your fly. As well, your rod will not always have the strength to pick up excess fly line out on the water, so you can't throw a mend as easy.
When you over-line your rod, you sacrifice distance. As was said earlier, more weight means more bend. Even subtle increases will affect the physics your rod was developed to perform under on the drawing board. Think about it this way - you can throw a baseball a lot farther than a basketball. The increased weight may not seem like much, but it carries a big impact. For this reason, if you are trying to launch casts far into the distance, you will probably not want to over-line your rod.
4 - Glass/Cane Rods
I once tried to over-line a small glass rod. When I put a 4 weight line on this 3 weight rod, you could feel the extra weight a LOT more than with the graphite rod. On a normal drift the glass rod would sag like a wet noddle. Even on my small streams I was having terrible drifts because of the increased weight. It was a sad cycle, as the rod sagging more meant more fly line on the water which in turn meant more drag. As well, the heavy fly line would cause my fly to drag terribly and the fly line would somehow find its way into every nook and cranny of the rocks that littered the river. Because I couldn't keep the line off the water.
That was a day wasted... or maybe I learned something...
I tried the same over-lined rig again another day, and the same drag occurred. I also tried it with a stiffer 5 weight glass rod I own - same result. After those experiences, I don't overlain glass rods. They already have enough bend, sensitivity, and load with such little effort that over-lining one is not worth it. This would include bamboo rods as well.
Like most everything in life, this is a balancing act. If you over-line your rod you will sacrifice things and gain things. Brief summary - you will be able to make shorter, accurate casts, but will sacrifice long drag-free drifts. You may be able to better get the timing of casting a fly rod better, but could also be forming a bad habit of relying on extra, unnecessary weight to load the rod.
I would recommend you trying it out to see what you like. I have tried it on every rod I owned. Some rods were an obvious no-go from the start, but others paired surprisingly well. It’s a fun task to try when the river is too far away or conditions aren’t good to fish (which is not often). With ten minutes in your backyard or a nearby pond you can feel the difference over-lining your rod does, and see what you like!