Light Spectra Line
Spectra is a very high strength synthetic rope with excellent abrasion resistant in a single braid construction. It comes standard with a polyurethane finish and is easily spliced using a lockstitch type splice, 4-3-2 or 5-4-3 tuck splice. It also has a low stretch, low creep, soft hand, is torque-free and it floats.
Here is an interesting article on using synthetic fibers such as Spectra for the standing rigging on a cruising trimaran: