Since I am no Spey casting Jedi, a word or two on my casting style is needed to qualify my findings when casting heavy sink tips - as the lengths and weights of heavy tips I found optimal, exceeded those recommended by several Skagit head manufacturers.
Firstly, I don't keep my hands close to my body, as recommended for two hand casting.
During the sweep, my right hand is swept around slightly behind my shoulder, then lifted into position very similar to when I make a regular overhead cast. The effect is that my single hand 9 ft rod becomes equal in sweep distance and lift to a double hand rod a foot or so longer.
Secondly, I always use a haul for my forward delivery, sometimes referred to as a turbo-Spey cast, delivered at the same time as I rotate my wrist at the end of the delivery - both of which further increase speed and power to load the rod and launch longer heavy sink tips.
There are two casts I found to be especially effective for casting heavy sink tips that go beyond the optimum length.
The first is a switch cast, timed so that the fly and only a few feet of tip are on the water when executing the roll cast, with a haul.
The second is a cast that begins by placing the fly and tip directly behind and facing away from me (e.g. with a modified Snap-T), so that the sweep lifts a good deal of the butt section of the tip off the water and the forward delivery is basically a water loaded overhead cast, instead of a roll cast.
Both methods work because they reduce ‘line stick’ by lifting the butt section of the tip above the water before going into the forward delivery. Since the sink tip is already aligned with the direction of the cast, before going into the sweep, energy is not expended on turning the heavy tip through 90 degrees when making the second cast.
It is worth remembering that the deeper one wades, the more difficult a heavy tip close to maximum length is to cast on a given rod and Skagit head. This is because there is an inverse relationship between effective rod length and wading depth.
When wading deep it is a good idea to choose a shorter head, and perhaps a longer rod - a shorter tip would be counter productive.
Several manufacturers produce sink tip series that have the same weight and length but with different sink rates.
In each of these series the tips with slower sink rate provide less line stick because: 1) they do not sink as deeply during the sustained anchor cast, 2) they are lighter in water, and therefore easier to lift. A 10 ft Sink 3-4 tip will therefore be easier to cast on a 9 ft single hand rod with 11-12 ft Skagit head than the Sink 6-7 version in the series.
By the same token, tips consisting of sections of increasing density - e.g. Rio 3D MOW tips - are easier to cast than an equivalent length of Level-T.
For example, a 10 ft 3D MOW tip in sink 3/4/5 is easier to cast on my 9.5 ft 5 wt rod than the sink 5/6/7 configuration, which is in turn easier to cast than 10 ft of T-8 (sink 6-7), even though all three tips have similar length and weight.
Single Hand Skagit - Science behind the magic
|+||Where it all began|
|+||Casting heavy sink tips|
|+||Shootout of 12 Skagit Heads I tested|
|+||Table of Sink Tip Recommendations|
|+||Table of Lengths and Weights of Sink Tips|
|+||How it all began|
|+||What is Spey casting?|
|+||Single versus two handed rods|
|+||Favourite Trout Spey outfits|