This is a nice little series about the difference between the Scandinavian and the Skagit systems. It is a 4 part series that is pretty simple to understand for the novice, and it has some great information for the experienced angler as well.

Just thought I'd share it...

Part #1 - http://www.jsrods.com/blog/skagit-or-scandi-pt-1-history/
Part #2 - http://www.jsrods.com/blog/skagit-or-scandi-pt-2-head-characteristics/
Part #3 - http://www.jsrods.com/blog/skagit-or-scandi-pt-3-river-conditions/
Part #4 - http://www.jsrods.com/blog/skagit-or-scandi-pt-4-recommended-casts-formulas/

Nice synopsis. Thanks for sharing.

Thanks Salmo. The goal wasn't to write an all inclusive encyclopedia, but rather something simple and informative for the novice caster. Once a certain level of skill is achieved, I think most (if not all) rules might be thrown out the window.

Big time help! Thanks. Now I just need to learn what length and weight sink tip to use to get down perfect, by just looking at the water instead of trial and error. Might be a new topic?

Getting the fly to the desired depth can always involve some trial and error. With experience, I can usually look at the water I'm about to fish and estimate what sink tip I want to use and whether I will use an unweighted or weighted fly. I'm finding my 15' type VI to be nearly universal, unless the water is significantly slower than average, in which case I switch to a type III. And if I can get deep enough by angling my cast straight out or slightly upstream, then I use a weighted fly. If that doesn't do it, I'm probably not fishing good fly water.

Sg

I think that's a great point! A lot of times, if it's too difficult to get the bottom, that may not be the bottom you want to be fishing (for Steelhead anyways). Here is a pretty interesting study done you may want to check out. It's definitely an enumerative result, but pretty cool none the less.

http://flyfishingresearch.net/flydepthrules/flydepthresults.html

I don't believe anything in fly fishing can be taken as 100% accurate all the time. There are too many variables to consider, but the information given here is worth taking time to consider.

A few years ago Ed Ward posted that if you aren't fishing deep enough with 9' of T-14, you're fishing the wrong water. I thought it was a good point, not universal, but kind of a rule of thumb.

I'm finding that I like longer tips on either of these types of setups, whenever I can make them work. Shorter tips make for better presentation tools, IMO, but if you can't get the cast to the lie, presentation doesn't mean much, so I usually make the compromise. With compact heads and tips shorter than 10 ft. or so, and especially on longer rods, I often struggle to keep my setup anchored when forming the D loop. That's probably the result of being a bit too aggressive on the backswing (read that as "my casting faults") instead of trusting the rod action to generate the speed and power. Anyway, using a longer tip and adjusting the grain weight down for the additional length, as opposed to using a shorter, faster-sinking tip, seems to help with that.

As for presentation, most takes seem to happen almost immediately after the fly starts swinging, and a big part of why probably has a lot to do with how the fly moves after it comes under tension. I think shorter tips probably cause the fly to rise away from the fish more quickly as it swims (maybe it mimics prey trying to escape and triggers a bite reaction). Whatever the case, figuring this stuff out is part of the fun of Spey fishing.