This would make an excellent halyard in the 3/16" which is really over kill but thick enough to handle:
www.knotandrope.com
There are many other choices. Search sailboat cordage.
AmSteel-Blue DyneemaGray/Silver / 3/16"
Strong as steel cable for it's size. This rope is easily spliced and has almost zero stretch. Rope Construction: AmSteel®-Blue is a torque-free, 12-strand single braid that yields the maximum in strength-to-weight ratio and, size-for-size, is the same strength as steel and it floats...
www.knotandrope.com

