Sort of a transplant over from a hollow core braided leader discussion in tackle talk - some good points put across and deserves it's own thread imo;
I use a similar system for my heavier saltwater flyfishing rigging, as you say it makes for nice smooth connections-and as you say-at full strength.
Really depends on what situation your thinking of using it.
But we use 50lb hollow braided mono, to form loops for the front and rear end of the line both soaked in aquasure, with the excess wiped off(normally a fast sinker), then another loop in the front of the backing. To connect to the fly line.
I like to put a piece of 50lb Mason (four foot of which will stand up on it's own) on as the butt section of the leader as it improves turnover. then loop on a class tippet/shock tippet section. If I am going after something decent then I will have several class/shocks set up with flies on a stretcher, if busted I can be re-rigged and casting in less than 30 seconds.
The back of the class tippet I tie a bimini and then twist it and tie a figure of eight knot, this with give you four strands of line to sprend the load and the twisted section acts as a shock absorber. Shocks 40-150lb fluro depending on species and conditions. Always worth having a few tied with 60lb single strand wire as well-blo*dy Cuda get everywhere.
I would look at Rio lines, as every Airflo line I have ever tried has been Cr*p, and got worse in tropical heat. I use a fast intermediate (instead of a floater) and Teeny lines from 250-750 off boats.
I would drop to 50lb gel for the backing-thinner, which slows the reduction of the arbor, makes it easier to get the fish back, plus 50lb will give you less line drag-important if you hook tuna/mackerel/wahoo.BE VERY CAREFULL DURING THE FIGHT-GEL UNDER TENSION CAN BE VERY VERY SHARP/DANGEROUS-I have the scars to prove it!!
Yes the stretcher holds the fly/shock tippet under tension, to keep them straight. just unclip the fly and you loop on the class tippet/shock/fly all in one go.
Core strength of the flyline is not worth worrying about-Unless you plan on pointing the rod at the fish and clamping the reel and using the boat to try and drag the fish away from a reef. Not such a good idea kit wise.A good #12 is lucky to produce 4lb of lift (Gen 2 Thomas & Thomas Horizons), so fishing anything over twevle pound class with a #12 isn't really increasing your chances of landing a fish.
Straight through shocks might sound easy, seen it done. Great way to blow a fly rod to bits. Better to make the effort, tye class 12-16lb leaders up now before you go. At least you will come home with a fly rod with the same number of sections it started with.
Hit and drag techniques better suited to spin/light stand up/jigging gear-where it is a well known way to fish for GT's.
Worth remembering that many of the biggest fly caught GT's have been caught with light drags, they then tend to run, rather than dive into the reef.
It has been done, guys do land GTs with 16lb tippets, but the ones that do are very experienced and are fishing for line class records. They also leave a lot of fish wearing flies. If that's what you want to do then fine but you are going to lose a hell of a lot of fish when they rub the leader on the coral. The 100lb leader is not for strength, its for abrasion resistance. Even with 100lb you will still lose a lot as you can't stop them in the same way as you can with popping gear. If you use the rod angles correctly and fight the fish low down you are applying a lot more pressure than 4lb. The rod is at a very flat angle and its land based fishing so you aren't dredging the fish up. We fought a near 100lb shark to a standstill on the flats and that fish wouldn't have even known we were there with only 4lb of pressure applied.
Been there, point the rod at the fish and wind up the drag way up, hardly using the rod-In fact NOT using the rod really. You will still leave just as many flies in GT's doing this. Only problem is recovering line, fly rods suck for pumping fish regardless of the angle. Heavy drags slow them down alright but won't improve your hooked to landed ratio's. Just feeding the sharks!! There isn't a big game fly reel around that will run drags heavy enough to pop 16-20lb class tippets, and shock/flylines cut just as easy on reef as class tippets. Scale the fish to the tackle, #12 is still UL compared to even spin tackle. Great fun for small GT's, Queenies, small tuna, King mackerel, but frankly is vastly undergunned for real GT fishing.
Seriously try lightening the drags. Most of the time the fish don't dive straight in a snag. Wonders well especially when using a popper/chugger. I grew up on the north shore of Australia, spinning and popping for Queenies, GT's, Tuna, macks etc etc. The harder you try to play GT's the faster they will try and snag you. We used to do 40lb+ GT's on 10lb mono. Gentle touch will keep them higher in the water. If you want to land Big GT's then go for glass spin rods (NOT CARBON), get a reel that will handle 25lb of drag, load it with 80lb braid and tye the best knots you know, swap your trebles/rings for 5X/150lb class stuff. Then you can bully them. Trying to bully them on fly gear is a waste of time.
I love big game fly fishing, I was lucky enough to be taught how to rig for it and how to fight the fish by Trey Combs. Frankly I doubt anyone will every have more experience of real heavy duty salt fly than him. But there is a time when fly SHOULD be replaced by spin/jigging gear. Big GT's are NOT very hardy fish, and prolonged fights do result in played to death fish-if the sharks don't get them first. Hardly a nice thing to do to a fish that may have been hanging around that bit of reef for a quarter of a century. Fish first fun second, as long as it doesn't unfairly damage the first.
Guys have been catching plenty of Gts on Cosmoledo and the other outer attols of the Seychelles for years now. They certainly don't soften off on the drag. Fight time for a 1m + fish on 12wt tackle is sub 30 minutes. Often a lot less. You can't do that fishing IGFA unless you're VERY experienced and know exactly how much pressure you can apply before the breaking strain of the class tippet is reached. And there would still be a lot of luck involved hoping the fish doest rub off your class tippet on the coral when he tries to knock the fly loose. Trey Combes can do this and does because he focuses on line class records and fair play to him. Someone who is less experienced is going to get smashed up a lot and if you're only there for a week you don't really have time to continually fail. Fishing a light drag will be fine and maybe you'll land the fish but you'd be standing there a long time and i wouldn't want to be chest deep in water when the big sharks come up on the flats at high tide.
When I talk about using the rod angles I mean using the low down power, not straight sticking. 1 pump, two winds.
I have caught LOT of GT, Trevallies, Jacks, on Spin, boat, and fly gear. From the north shore of Australia to Kenya to Christams Island. Never had trouble with class tippets that are IGFA legal. I have seen lots of blown rods through "straight through" set ups in the hands of inexperienced or over excited anglers. Basically like putting 100lb braid on a rod designed for 20lb braid and then trying to lean on it.
Fishing over the sands on the atolls be it Seycelles or Christmas Island is probably the easiest place in the world to handle good sized GT's, but #12 are simply undergunned against fish above 50lb class. I will bet on the sharks/dead fish every time. Low down power is a factor of the reels drag setting-not the power of the rod, it is straight sticking. Which is a valuable method for fighting fish. But without a class tippet, a broken rod is only one tiny mistake away.
David I have tested to breaking most of the decent saltwater fly rods, even getting four pounds of tippet pressure will blow most of them. Even most #15-17 struggle to generate more than 6 lb of lift. Be it Sage, Loomis, T&T, Scott or whoever.
Fisher (if you can find one of the real ones) are simply in a different class power wise. Their #12/13 will lift 5lb off the floor. I have nailled sails, tuna and alsorts of bluewater fish on that rod paired to a tuned Tibor Gulfstream. And it is simply not man enough to handle decent sized GT's.
As for the Trey, I know no-one more concerned with releasing healthy fish. He plays fish to the max possible on the gear he is using-not stunt fishing for line classes.But so he is able to release them quickly. No one I know of knows more about squeezing every last ounce of pressure of fly tackle. But check out what he has to say about the #10-#17 fly rods and the power they are able to deliver. Fact I have seen the testing.
Short of custom built gear there is no fly rod available that will break 16 or 20lb class-only angler mistakes will do that. Although many might like to think straight allows more pressure to be applied-it is simply not true.
As for carbon rods, check out the differences in the elastic limits (which is where lift is limited in carbon rods) between glass and carbon rods. Then have a look at what the Australians use for GT's-and they DON'T like feeding the sharks. High tech isn't always the best way to go-hence why you don't see many carbon big game rods!!
Anyway Happy to talk to you Alex about rigging heavy fly gear-used to do it for a living so should be able to talk you through it.