In the May 1999 column we were the first to report on the results of an important strength and reliability study of safety harnesses and tethers. While almost all the harnesses passed strength and comfort tests without distortion of D-rings and other hardware, almost half the tethers (the lengths of webbing or line that connect the
harness and its wearer to the boat) failed in strength tests that put a heavy shock load on the tether. Among the tethers that failed were some sold by Captain Al's; they have since been redesigned and have passed the test. In most cases the hardware failed, yet the tethers themselves can be weakened by sudden loads and prolonged exposure to ultraviolet rays. Replacement tethers should be carried on board so that a tether that has come under heavy load or been out in the sun for any length of time can be replaced.
The harness/tether study was conducted by one of the most effective of today's boating organizations, the Sailing Foundation of Seattle, Washington. Founded a quarter-century ago to assist sailors in the Seattle area, for many years the Foundation has also been conducting cutting-edge research on safety gear and techniques. Its people (all volunteers) developed the ingenious but simple LifeSling crewoverboard rescue device - a breakthrough piece of equipment that has saved many lives and, I strongly believe, belongs on any boat larger than 24 feet. 
A valuable ongoing project, Matt Pederson of the Foundation tells me, is to study materials for jacklines (the lines on deck that safety harness tethers hook on to). In the Sydney-Hobart there were complaints that webbing jacklines (which I favor) stretched too much. The Foundation will test webbing, wire, and high-tech rope, like Spectra, Matt says. "There's been suggestions from the US Sailing Safety-at-Sea Committee that we pursue the tether hardware issue in more depth. We're also in the very preliminary stages of a storm tactics study. We're busy with a Safety-at-Sea seminar for February, and the Foundation has received a patent for a combination strobe/incandescent crewoverboard light. We're working to make that a commercial reality."
That's quite an agenda of good works. Membership in the Foundation supports these activities, so you may want to consider joining me in sending $25 to The Sailing Foundation, P.O. Box 4213, Tumwater, WA 98501.