Featured Product & Trout Spey Pro Tip - SA Sonar Leaders

Featured Product & Trout Spey Pro Tip - SA Sonar Leaders

Here at Big Sky Anglers, we have absolutely fallen in love with the Scientific Anglers Sonar Leaders for Trout Spey (and other) applications.  They have become our go-to “sink tip” option for 3wt and lighter Trout Spey rods, and for converting the RIO Trout Spey shooting heads and light Skagit heads into super smooth casting and fishing tools.  They have even found a place in our stillwater angling bag of tricks. 

"So, what is a Sonar Leader?"

Simply put, it is Scientific Anglers' take on the “coated, tapered leader” concept.  If you are familiar with RIO Versileaders or Airflo Polyleaders, these are similar, with what we feel are a couple of advantages worth noting.  SA’s Sonar Leaders come in 7 and 10-foot long versions (35 and 50 grains respectively), include a welded loop on the butt end, and feature a 25lb test monofilament core, and NEW FOR 2023 - Sonar leaders feature a micro-swivel on the front end to reduce line twist. They come in six densities, including Floating, Hover (1 inch per second sink rate), Intermediate (1.25 inch per second sink rate), Type 3 (3 inch per second sink rate) and Type 6 (6 inch per second sink rate).  Especially cool is the fact that they are labeled with text identifying each one.  For example, the 10ft, 50 grain, Intermediate Sonar leader is labeled with “ SA SONAR LDR 10FT 50GR INT”.


"What are Pros and Cons?"

As far as what we really like about these SA Sonar Leaders, let’s just start by reiterating that they are individually labeled with text, right on the leader butt, identifying which leader is which.  No more trying to remember which color leader is which.  No more having to look up which leader has a red loop.  And best of all, no more having to unroll the whole leader just to find out it’s the short one, when you wanted to use the longer one.  Another thing we really like about these are their durability.  They really seem to be holding up to the abuse, with the loops staying intact and the core bonded to the coating nicely.  Lastly, we really like the 25lb test core strength, so that even after a bunch of use, and potential for nicks and scrapes down at the tippet end, there will still be enough extra beef to pull hard on 1x or 2x tippets.In terms of things we don’t love about these leaders, there really isn’t a whole ton to say.  

The addition of a micro-swivel to the terminal end of these leaders is a fantastic improvement that dramatically improves durability and ease of rigging. 

"How do you Rig one?"

 When rigging these for Spey applications, we tend to prefer at least 4-feet of added tippet, and often as much as 6 or even 8-feet of added tippet on the floating and hover versions with soft hackles.  For those extra long applications, it can help to actually add a tapered tippet using 3-4 feet of 0x, 1x, or 2x and then blood knotting or surgeons knotting on another 3-4ft of your choice terminal tippet of 2x, 3x, or in some cases maybe even 4x (though we have rarely if ever found 4x necessary while swinging).

Keep in mind that, over time, any rigging will begin to wear, and replacing the micro swivel will be necessary.  So, keep an eye on it, and replace when things are looking warn.  The good news is that the 25lb test mono core can take a ton of abuse before it needs to be re-tied.

"How do you Use One?"

Our favorite use by far for the Sonar leaders has been for Trout Spey applications.  In particular, the 10-foot long Sonar Leaders, weighing in at 50 grains, has proven itself to be a fantastic, light sink tip option to attach to Skagit heads that match 3-weight and lighter trout Spey rods.  We’ve found that Skagit heads weighing 300 grains or less have a much easier time turning over a 50 grain Sonar sinking leader than a level sink tip of T-8 (80 grains at 10 feet, or 100 grains at 12 feet).  The tapered front 3 feet of the leaders also seem to smooth out the turnover and take a bit of the clumsy “WHACK” associated with Skagit heads when used to throw lighter flies like small buggers and soft hackle teams.  

We’ve found these leaders to be especially dreamy when paired with RIO’s Elite Trout Spey Shooting Heads.  By adding the tapered Sonar leader it essentially allows the angler to create a sort of multi-tip, 33-foot long Scandi line that is able to smoothly and sweetly turn over soft hackles and smaller streamers with relative ease.  For those who love fishing soft hackles throughout the entire water column, and occasionally throw a small bugger, this could be your dream line/tip kit.  For Spey applications, our most popular Sonar Leaders are the 10-footers in Intermediate, Type 3, and Type 6 sink rates.

In fact, we have found the SA Sonar Leaders to be the missing link in many of our line recommendations in this year's Trout Spey Rod Review. The perfect combination of extra length and mass found in these leaders is a critical component to dial in the set-up for your favorite Trout Spey Rod. If you haven't already, check out the review for more line recommendations on 22 of our favorite Trout Spey Rods. 

Another application that a couple of our staffers have found for these SA Sonar Leaders is on the lakes.  Adding a sinking Sonar leader to the end of a standard floating fly line creates a type of sink tip or “midge tip” that can be very effective for presenting emerging nymph and pupa patterns in an upward curving ach path that exactly imitates the behavior of naturals.  They are also a great option for your slow creepin’ nymph and leech presentations right above the weeds in water less than 6 feet deep.  On stillwater, we tend to gravitate to the 7-foot sonar leaders and definitely have found that looping them to flylines with shorter, more aggressive front tapers results in easier casting, but the 10-footers also have a place.  Adding 6 to 8-foot long, level tippets or tapered fluorocarbon tippets as described above creates necessary separation and invisibility required to fool sometimes fussy stillwater beasts.  For stillwater applications, our favorite Sonar Leaders are the Hover, Intermediate, and Type 3 sink rates.

So, whether you are looking for a versatile way to dial in your favorite Trout Spey set-up, or up your game in stillwater situations, the SA Sonar Leaders have proven to be a great choice. 


trout spey Review

A few of us Spey Nerds here at Big Sky Anglers decided to pull together a sizable pile of rods, lines, and other gear, make an effort to dial in as many kits as we could, and share the results with you all.

Read the Review

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