Line thickness

[DogDiver]

Hi-vis braided Dacron line used for deep sea fishing is available from: theropeguy.com

[phillip1]

I just was knotting the Dacron Line from rainbownet, now although it appears very tough the manufacturing quality is terrible, even worse than Dominican twisted nylon twine at he hardware store.
On all the spools I have the line has had 1-2 splices right in the middle of the spool and held together by a makeshift knot, and out of 8 reels three were frayed to the point that I had to splice the line. All the spools had weird pressure kind of marks, that will not affect strength but still this is new line right of the spool!!
You really need to inspect every spool and the entire line fully.

On the plus side as I said above it seems really tough, tougher than nylon line and it is much harder to tangle that nylon line, it is very flexible and "snakes" so to speak and does not coil at all when loose.
It has been raining real hard here for the past week so we have not been diving but I will be using the line in a very sharp rock cave and one that also has flow and debris flying out and stuff so this Dacron line will be put to the test in the next week or so and will report back on how it works.

At first glance it looks much stronger and has better tangle resistance than nylon

[DA Aquamaster]

Dacron is just a trade name for polyester. Nylon and polyester ropes are about the same strenght when dry but polyester is stronger than nylon when wet as nylon loses up to 25% of its tensile strenght in water.

On the other hand, nylon is very stretchy and absorbs shock loads much better than polyester. In that regard, nylon has a lot going for it in terms of how it would handle getting stretched, hit, etc in a cave.

The bad news for polyester/dacron line is that it is not very resistant at all to chafing, and chafing is pretty much an everyday circumstance for cave line, so I suspect dacron may not work out as well as you hope, especially in a hard/sharp rocked cave with lots of flow.

[phillip1]

I was just talking to some fishermen here who make nets and they said the exact same thing as you, that dacron is not as resistant to chafing etc.. I think we will test a small section and probably end up using regular nylon line.
The main thing I need in that cave and any cave for that matter is resistance to chaffing, so it probably wont work so well

[FW]

I was just talking to some fishermen here who make nets and they said the exact same thing as you, that dacron is not as resistant to chafing etc.. I think we will test a small section and probably end up using regular nylon line.
The main thing I need in that cave and any cave for that matter is resistance to chaffing, so it probably wont work so well

It in more a function of how the line is made, than material. I am still working to get the tightly sheathed Dacron line available. It has done very well in abrasion testing.

[phillip1]

the one I got is a super tight weave around a core. It looks like it will hold up very well

[DA Aquamaster]

It in more a function of how the line is made, than material. I am still working to get the tightly sheathed Dacron line available. It has done very well in abrasion testing.

I think a kernmantle type construction with a nylon cover (abrasion resistance) and a dacron or Spectra core (high strenght, low stretch) would be ideal for some situations.