• Welcome to the DeeperBlue.com Forums, the largest online community dedicated to Freediving, Scuba Diving and Spearfishing. To gain full access to the DeeperBlue.com Forums you must register for a free account. As a registered member you will be able to:

    • Join over 44,280+ fellow diving enthusiasts from around the world on this forum
    • Participate in and browse from over 516,210+ posts.
    • Communicate privately with other divers from around the world.
    • Post your own photos or view from 7,441+ user submitted images.
    • All this and much more...

    You can gain access to all this absolutely free when you register for an account, so sign up today!

Homemade floatlines, Some ??'S

Thread Status: Hello , There was no answer in this thread for more than 60 days.
It can take a long time to get an up-to-date response or contact with relevant users.


New Member
Apr 12, 2002
I am in the process of making my own floatline. Ive got some nice urethane tubing, some 600# tuna swivels, & evan some heatshrink tubing to finish the ends. I am having some trouble finding some cord for inside the tubing. Ive looked at Dacron but cant find any with a breaking strength over 200# I have seen alot of nylon that looks right (size dia.) but the breaking strength is not listed. Ive evan looked at mono but dont think I will able to cram enough inside the tubing to get the stretch I want(too stiff) Has anyone made there own floatlines? What did you use? Can someone tell me what to use with a breaking strength over 400# & where to get it? Cost is also a factor.

It used to be green and they called it tuna line. When I asked for some at the fishing store here, they gave me grey stuff that is better. Don't remember the price. Works great. I think they call it handline.



email cherryl at freedive@starband.net and ask her about dynema for your floatline. they use it primarily for wishbones, but aquiles and others are using it in their floatlines. i think it's about 500lbs strength and tough as nails. soft and supple, too.

good luck,

Iregularly make bungee floatlines, one's in the mail to Andrsn at the moment. The previous one got lost in the mail - I hope this one makes it!

I use Latex tubing for the outer, and either Dacron / handline or parachute chord for the inner. You can get para chord from most rock climbing - type shops, it tends to get pretty expensive though. But you can get nearly any color / size / breaking strength combination you can think of. That'll probably be your best bet.
All the dacron I have found is very small in dia. maybe 1/32" thk & a breaking strength of about 200# how thick is the dacron handline you are using & what is the breaking strength.

I will also look into Dynema & try to find some parachute cord.

Thanks for all help guys,

It all depends - for the average float I use a 50 to 70KG breaking strain. This is sufficient for most fish that you'll encounter in Blue Water.

For serious heavy duty use I get 100 - 110 Kg breaking strain. More than that and the line's too thick. That's really heavy duty stuff, I've never broken one of these. I've also never broken a 'performance' line, which is normally a 45kg's monofilament inner. I have, however, broken a 60kg line - but that was more stupidity than fish. And yes, it was another Tuna.

I've turned to using dynema for a multi-purpose line, you can really abuse these things. Rocks etc's not gonna make a difference. One thing to remember though is that dynema takes up water - you have to use either resin or another hard plastic to seal the ends - otherwise the line's gonna rot inside the tube.

Slick rick

Hey Rick,
Go to your yellow pages and look in the fishing supplies section for a place in your area that handles longline gear. They'll have the tuna or gangion/drop line that Bill (and I) recommend- it's cheap and it'll put the brakes on a bigger fish than anyone here will see or shoot. TThe dynema is also really good, tough stuff, but as it's going in the urethane tubing, it's going Ferrari when you need a truck. It's great for quiet wishbones though.

Regardless of what material you use, tie the knots or make the crimps in such a way as to not compromise the line. The best line and a lousy knot equal a big regret.

I've alway's used latex rubber bungee with paracord for mine - someone want to elaborate on Dynema?
Hi Amphib:
Dynema is one of the synthetic super hi-strength/size fibers. Probably in the same family as Kevlar or Spectra if it's not the same thing w/ a different name so the can charge more.
Dynema = Spectra

From different companies. Little Rock climbing knowledge thrown into the mix ...
I figured it had to be close to the same thing. We use it for towing and mooring lines, but its called Spectra in the marine industry. Although we use stuff 6-8" in circ. it might be a bit large for a float line but it won't break.:D
Hey there FLRick,

I make all of my floatlines. I use 3/16 vynil tubing that you get from say home depot. It's usually from 6-9 cents a foot. I also use dynema that I get from florida freedivers for 27 cents a foot. I also use 400 lb aussie swivels to attatch it to the gun and the float. You will also need a good sealant. I use 5200 by 3M. I make my floatlines 100feet long. Use a vaccume cleaner or an X-girlfreind :rcard and use a light monofilament line attached to a cottonball to pass the line through the tube. If the humidity is high then you can pass a small bit of talcum powder to make the line slip easily through the tube. When this is done then you pass your 115 feet of dynema through; be careful not to pull to fast. Next tie two bolines to the swivels and crimp them for added security. Now this is the messy part......:( put your sealant in the tube and force the swivel down behind it. Tie two clinch knots on the tube and add heat shrink for good looks.:king Now your golden. Let the sealent set and your ready to go. If you want to see a pic of the finished prod, email anderson and I am sure that he has a pic of one of my setups that he can post on the site for you :friday now its miller time