spectra line on Reel

[dumpsterDiver]

I'm just curious, in the last few years a braided synthetic line is now available that is much stronger and more abrasion resistant than the nylon line that divers normally use. Are cave divers switching over to the new stuff? It seems like it would be a significant improvement? Is the cost too much relative to nylon line?

Q Powerline (q line) - 500ft spool (600lb) Q Powerline kiteboarding control line [qline] - $125.00 : Green Hat Kiteboarding, Kiteboarding / Kitesurfing Lessons and Equipment - NJ, NY, PA

 

[SuPrBuGmAn]

I might be offbase with this, but I think we use the current US standard braided line because it sinks.

That being said, I have no idea what this stuff does. Might be a good alternative if you want to pay triple(or more) the cost for less length?

 

[Underwater Ogre]

I don't know about the smaller diameters but I have used a lot of Spectra 1/2" and up...it sinks like a stone.

U/O

 

[DA Aquamaster]

I used to use Spectra when flying large stunt kites. The big advantage in that application over nylon or dacron is that it has very little stretch so the commands to the kite are much more precise and it gives a much more exact feel when flying the kite. The other advantage is that with kite flying it is common for the two control lines to be crossed or wrapped several times for most of the flight so they rub against each other and extra abrasion resistance is a good thing.

In a cave however, I'd avoid it like the plauge. If you snag yourself on a braided nylon line, one of the indications will be the slow increase in tension as you begin to stretch the line - becuase it stretches. That stretch also ensures that the energy from any diver contact or pull is dissipated slowly over the lenght of the line reducing the tensile strenght required compared to a line with very little stretch (lines with little stretch have to be stronger to avoid breaking).

Plus repairs are more easily made with nylon as you can stretch the line slightly to re-tie the broken ends of a line rather than having to splice a piece in on a line that does nto stretch. And, if you spliced a piece of line into a spectra line, the very limited stretch would make it more difficult to ensure the line was tight after the repair was finished.

I am not sure if spectra sinks or not, but bug is correct that one of the reasons nylon is used is that it sinks.

"Stronger" is nice except that more strenght is not really needed in cave diving and smaller line diameter does not offer any particular advantage as below certain point the ability to increase the lenght on a spool is offset by poorer handing traits - you want to avoid tangling your line as much as possible and on balance braided nylon line handles quite well.

Finally, I can pick up 500' of braided #18 or #24 surveyor line for $4 or $5 at the local hardware store and I can get a 1200' or so of #24 in a dive shop for around $25-$30, so when the nylon line on a spool gets worn it is cheap to replace. If divers are paying 10 times that much for line, they are going to be a lot more hestitant to change it whenever it finally needs changed.

 

[GrumpyOldGuy]

Hijack / Spectra Story

While at Woods Hole with a group of scouts one of their experts proudly showed off their new multi-million dollars core sampling system. Key to this was a gigantic spool of Spectra cable, about 2 inches in diamater and many 1000's of feet long. He went on and on how it was stronger and lighter than steel and how expensive it was. He showed of a huge tensile strenth test jig they used to verify the cable and other cool instrumentation.

He had a sample length and at then end, one of the boys asked if he could test it with his $5 pocket knife. He said yes, we all expected him to attempt to saw through it and dull the knife. To our amazemet the pocket knife sliced through it in seconds.

 

[Underwater Ogre]

Another hijack story...

We were using 3/4" Spectra for a winch line, someone had ran the line over one of the sharp torsion bars instead of through the davit on the winch. After 3 hours of up and down hauling, the operator complained the slack was releasing as well as it should. When inspected there was a bit of fuzzy on the sharp bar, but barely it took anything off of the rope.
GrumpyOldGuy is right, it cuts like butter but chafing is a whole different story. Also when a knot is tied into it and pressure is applied it will weld the knot together, takes a hammer to beat the knot out. Quite impressive. But it should be for the price.

 

[dumpsterDiver]

Thanks for the info.. I was just wondering if/when it would be accepted.