Fly Lines - Tropical V Coldwater

[Mike Barrio]

It would seem pretty obvious that you should fish a tropical fly line in the Bahamas and a coldwater fly line in Scotland in March, but are they really any different?

The words tropical/coldwater are just added to the blurb to sell us more lines right? Well no, they are usually manufactured differently, a tropical line will typically have a stiffer monofilament core and a harder coating, a coldwater line will typically have a more supple multifilament core and a softer coating.

If you fish a tropical line in colder conditions you will possibly experience memory problems where the line will coil and tangle. If you fish a coldwater line in hotter conditions the coating can go a bit soft, limp and sticky through the rings.

We don't discuss this much in Scotland as we tend not to fish rivers on hot sunny days, or if water temperatures reach 18 to 20 degrees Celsius and the fish are best left alone. Fishing stillwaters in hotter conditions is not so unusual and this is where we could possibly notice how a coldwater line can start to lose performance.

Our fly fishing cousins in warmer climes discuss this more frequently, in the States they often speak about 'up to 70-75 Fahrenheit' and 'below 70-75 Fahrenheit' for example, which by my calculations would be around 21-23 Celsius.

So what might we possibly encounter in Scotland?

Tropical lines: these can start to experience memory/coiling issues in water temperatures below approx 15 Celsius, and/or air temperatures below approx 20 Celsius. So they typically perform best above these temperatures.

Coldwater lines: coldwater lines are very much the bread and butter when it comes to fly fishing in Scotland, the benefits of their suppleness when fishing our waters are clear and without question, but it is worth remembering that even in our climate, these can start to lose performance in higher temperatures.

Coldwater lines typically perform best below water temperatures of approx 15 Celsius, and/or air temperatures of approx 20 Celsius, and can start to lose performance above water temperatures of approx 20 Celsius, and/or air temperatures of approx 25 Celsius.

What are your experiences with tropical and coldwater fly lines?

[Hamish Young]

What are your experiences with tropical and coldwater fly lines?

That's an interesting question Mr B.
Not all that long ago (well, probably less than 20 anyway) I chopped up a floating tropical fly line for its running line and then used it as the running line for a Salmon weight shooting head. It worked a treat, albeit it was a tad prone to coiling, but I expected to endure the coiling as the upside was 'shootability' - it went like the proverbial from a teflon coated shovel. I moved on to things like Varivas Airs, which I still use today.
I've never used a tropical fly line where they are intended to be used, but I have a reasonable stash of these lines and I am curious to see during the summer if they are still too much of a compromise.

[Duncan Inglis]

I bought a Scientific Angler from memory floating line when on holiday in the Keys, this was a good few years ago. Tried it when I got back to Scotland and it was lying in coils like barbed wire, couldn't get the memory out of it even in summer in Scotland.
Went to the Bahamas a few years later and it cast and fished beautifully