Classic Hawaiian slings are freeshafts, meaning they do not use a shooting line. Consequently, they are usually used in clear water on fish that hole up after they are shot. On most days in Northern California, a freeshaft means a lost shaft, or if you hit, a lost fish. So, why not add a shooting line?
Some people argue that adding a shooting line to an Hawaiian sling defeats the purpose. You sacrifice the rapid reloading capability, and turn a simple weapon into a complicated one. Still, if you are stuck in murky water hunting fish that run away, you've just got to have a shooting line on your sling.
There are numerous considerations to take into account concerning the shooting line. How long should it be? What material is best? How should I rig the line? Some observations and ideas follow.
Hawaiian slings don't have much power so you don't need 15 feet of line. Too much line can also be a pain to manage, so shorter is actually better. A good length for line is just over the length of the spear. If you are using a 48" shaft, somewhere around 54" is about right.
To make the line easier to manage you may consider attaching a sliding lead weight to the shooting line. This will keep the line going straight down, well organized, and out of the way. A swivel-clip is also a good idea. The swivel will aid in avoiding line tangles and the clip will allow you to change (or abandon) shafts easily. I have found the best swivel-clips and weights at fishing stores (no surprise there). Unlike spearguns, Hawaiian slings do not need a bungie shock-line. The sling just doesn't produce enough power to make that a necessity.
Since you won't be hunting 100lb fish with an Hawaiian sling, you don't need a super heavy shooting line. The line you choose should resist the elements and abrasion, should handle easily, and have minimum drag. Some candidates are:
Monofilament (weed whacker line for the budget-minded, Jinkai for the rest)
Mono is easy to handle in the water as it doesn't tangle easily. Its also very low drag so its a really good choice. Although it sounds like a lot, 200lb test is a useable size. The other lines are all braids and share some of the same disadvantages: they cause more drag, they can saw through the flesh of a fish, they are limp in the water making the line difficult to control. Still, braided line, especially hardware-store-variety braided nylon, is cheap, easy to work with, and readily available. Braided nylon comes in different grades, the best I have found (resembling the tight braid on Riffe Kevlar) was called "Contractor Grade".
Here's what Rob Allen at the Dive Factory says about mono and Spectra. He's talking about heavier line than you would use on a sling, but the information is still valid.
We've run many tests on Spectra, mono nylon, crimping and knots. We have found if crimping mono, use the double barrel type crimp. This must be fitted with the correct crimp tool. A standard barrel crimp, crimped with a cable type crimper will damage the line and weaken it. The design of the double barrel type places an equal pressure all around the mono. When crimping the mono, do a load test. We test the break strength of the crimps on the 300 lb mono and have managed to get around 200 lb break strength when the crimp is crimped correctly. You will always loose break strength at the crimp or at knots. We have found the crimp to be stronger than knots on mono and has a lower profile. Mono is good because of its stretch, ease of handling and costs. It also does not absorb water and slow the spear down like all the multi-fibre type cords.
Spectra or Dynema as it is known here, has a much higher break strain. Dynema, 10% thinner than the 300 lb mono, has a break strength of 570 lb. If knotted, you loose up to 50% of the break strength. Having no stretch also means that it is important to fit small bungies on the shooting line. Disadvantages are the cost and the difficulty to handle in the water. To maximize the break strength, it is best to sew it together rather than tie. This keeps the break strength at its full break strength rating and is low profile. Abrasion wise, we have done bench tests on sharp/rough objects and found the Dynema to be much better than that of the mono nylon.
Rob Allen
Dive Factory 181 Gale ST Durban RSA
Tel: +27 31 301 2241
e-mail: divefac@iafrica.com
Website: http://www.divefactory.co.za
Most European spearguns have their shooting lines attached this way, so that's why its called "Euro" style. When rigged this way the shooting line is attached directly to the end of the spear. The main requirement is that the barrel must have an opening wide enough to allow the spear and the line to pass through without catching. The minimum size for this is about 1/2", though larger is probably better.
Drill a 3/32" hole towards the rear of the shaft. If you are using mono, crimp it and be done with it. If you are tying a knot, drill a larger hole (3/16" is about right) over the first hole about 3/4 of the way down. This larger hole will hide the knot. Chamfer the edges of the small hole so it won't cut the line. Feed the line through the hole and tie an overhand knot. Depending on the line you are using you may need to melt the end of the line to keep it from fraying/pulling through.
Slide rings are often used on American spearguns, like A.B. Biller and JBL. You can buy slide rings from various manufacturers, with the best ones (for this application) being the lightest ones. The best slide rings I have seen come from Riffe and are meant for their slip tips. The slide rings are a bit on the expensive side ($13), but the lightweight design and superior quality offset the expense. They are available in 4 sizes so they should fit whatever shaft you have (unless its metric or 17/64").
Making a slide ring is pretty easy, too. A 1/4" nylon spacer can be converted into a fine slide ring by cutting a small band around the spacer to attach the line to. These same spacers make great shaft cups, too. Instructions for that are covered in the section Inexpensive Hawaiian Slings.
A slide ring must have some kind of bump that the slide ring will stop against. One easy way to make this bump is with a rivet. You don't need a full length rivet, so if you ground the rivet off a flopper (and didn't throw it out) that will do fine.
Start by drilling a 3/32" hole (the standard size for flopper rivets) just ahead of where the butt of the spear engages the cup. Slide the slide ring on the shaft and then install the rivet. Bang on the rivet to make it as flush to the shaft as possible. Important: Before you set the rivet make sure the slide ring really is on the shaft.
A slide ring gives you the option of using a slinky cord. Instructions for making one are in the section Making a Slinky Cord.
We're still working on which way is the best way to rig a shooting line. Probably there is no "best way", as it just comes down to personal taste. Stay tuned for preliminary results.
Update: If you are using a nylon spacer for the slide ring, install a washer behind the spacer, otherwise the spacer may jam on the rivet. Also, to attach the mono, crimp a small loop ahead of the spacer. You do not need to attach the line directly to the slide ring, as the mono will slide down the shaft just fine.
Update: I got a letter from Mike Messina in Florida. He rigs his shooting line through the front of the spear, so that the line does not need to go through the tube. My initial instinct was that this may be less accurate. But for most shots, which are probably five feet or less, probably it makes no difference at all.