How are you? I was wondering if you could give me some ideas on what type of leader you recommend for swinging Spey flies (size 1.5 to 5 Daiichi Alec Jackson Hooks) on the Salmon River in NY? I've been fishing the 750cfs flow. I'm using a 13 foot Dec Hogan with a Balastic Scandi Head. Any help would be appreciated.....since I'm still very new to the Spey.
So, on the Salmon River where casting room is limited at times and you are wanting to use larger Spey style flies and you need to use sinking tips and poly leaders, I go with the Skagit. You call your favorite line company and you tell them the rod you have and they will match the line grain weight exact to the rod. There are both integrated as well as heads available. I am using the Rio system and changing heads as needed.
Now, you need to have a collection of tips. Tungsten gets you really deep. These you make loop to loop connectors 3 feet, 5 feet, 7.5 feet and 10 feet. The longer the tip the deeper you go. You will also want to have a collection of poly leaders. These are tapered coated mono that are available from a wide range on vendors in lengths and sink rates. You could easily buy 20 different heads today. I first purchased poly leaders while fishing in Scotland when no company or store in the US(well, East Coast Anyway) ever heard of them. Today they are a standard. Make sure you check the strength as there are now trout options and I go for the 20-24 pound strength.
Tippet is connected to the sink tip. This now varies depending on depth and the sink tip you choose. Last week I was fishing Atlantic Salmon in Nova Scotia and the water was up a bit. I used a 12 foot poly at 6.4 inches per second sink rate with a 10 pound Maxima at 18 inches. The longer the tippet the higher the fly will ride from the bottom. This is something you need to experiment with. When swinging flies for Steelhead the leader does not need to be as small as when indicator or nymph style fishing. The leader is always behind the fly and the fish really can not see it well from that angle. If you like fluorocarbon, there is no need to go lower that 10 pound test. I do not taper the leaders.
The last piece to the puzzle is how do I keep my fly fishing deep without loosing too many flies on the bottom. I am working on an article right now called "Loosing weight one shot at a time" I am building trout and Steelhead flies weighted so that the hook rides up and the Spey flies are built up side down. The amount of weight in the fly is another factor you must understand when choosing the fly on the piece of water you are fishing. This is not a new concept but one that is not available to the non tier.
So, I hope this helps a bit. If you want to stay with your Scandi, then just do the same thing as I say off the tip. It will be harder to cast and use more room around you but it will work.
If I can answer more specific questions please feel free to ask.
Always the very best,