[Stumble]

I would point out that the use of the line as an external halyard doesn't really change the calculus much when dealing with dyneema. It is almost impervious to uv degradation, and chaff.

Personally I won't use Dacron for much of anything, since it stretches a ton, and has a poor lifespan due to uv damage, and age weakening. Plus it looses strength when wet... It just seems a poor material for use in marine environments. I would go with at least sta-set since it holds up better.

The other thing I didn't mention is expected lifespan. It has been years since I bought sta-set, but as I remember it gets really stiff and hard to manipulate after just a couple of seasons. My amsteel halyards are still supple and soft after 4 years in the sun (new Orleans area). I keep checking them for replacement, but I haven't seen any degradation that indicates replacement is imminent.