Bill Tuthill wrote:

Jeremy wrote:

That's useful feedback. I was considering replacing my polypro line with the
equivalent width spectra. The polypro started out nearly bath towel soft,
and is probably almost as strong. Have you found a better dual-use line
suitable for carrying in a kayak?

Based on specs below, I am going to buy 50' of Yale Conception 6mm (1/4")
to replace the braided Polypro that came with my $27 Kayaker's Throwbag.
http://theboatpeople.com/atr_safety.html#throwbags
The 50' of braided 5/16" Polypro will become the new bowline for my raft.
I'll report back after initial use. NRS Spectra might be Blue Line.

tensile cost/ft #/100ft handling
NRS Spectra 6mm 2500# $.80 1.6# stiff and abrasive
Yale Conception 6mm 2500# $.62 1.4# soft hand?
Yale Conception 8mm 4100# $.95 2.0# soft hand?
Bluewater Polypro 8mm 1900# $.56 3.0# core, but handles well
NRS Spectra 10mm 4966# $.99 3.4# semi stiff, not bad
Yale Conception 10mm 5500# $1.32 3.5# soft hand?

What makes Yale Conception unusual (easier handling characteristics)
is that the Dyneema is braided together with Polypro. This makes it
lightweight, soft, and unitary. Blue Line(?) Spectra has an inner core
that makes it very stiff, and the Polypro sheath behaves differently,
and comes apart from, the Spectra core. This is OK in a 10mm (3/8")
line, but I just don't like it in a 6mm (1/4") line.

I think you'll like the Yale Conception. It is quite soft, not at all
stiff, very lightweight and pretty grippy. I've been using it as a
mainsheet for two seasons of hard use, and it's held up pretty well.
Note that it runs a bit fat and tends to flatten out when cleated, but
that's probably not an issue for your intended usage.

I respectfully withdraw my concerns about ultra low stretch lines as
throwables, other than the increased cost. Of course, if you are ever
in a situation where it really makes a difference the extra $50 is
pretty darned irrelevant in the greater scheme of things.

//Walt