Your Marine Sanitation Device Specialists Discuss Which Safety Tether Material Is the Strongest

Raritan Engineering your marine sanitation device suppliers would like to share with you this week some great information regarding find the best safety tethers for you.

A safety tether keeps you safely on board, but it also comes with its own risks.

How much impact, are we talking about? Enough to break tethers. In the 1998 Sydney-Hobart race, Glyn Charles was lost when his tether parted during a rollover. As a result of this accident and some shocking follow-up tests, World Sailing (then ISAF) adopted a new drop test for tethers.

What We Tested

Searching for an ideal combination of stretch and strength in a tether, Frye tested various webbing and rope materials, as well as a fall-arresting device approved by the Occupational Safety and Hazards Administration.

Rope is used less frequently because it can roll under your feet, but small diameter ropes are less troublesome. In the lab, Frye tested webbing from a lightly used production tether, one-inch climbing webbing, two sizes of climbing rope, and Amsteel, a high-tenacity 12-strand Dyneema rope from Samson. 

Often sailors believe that the elastic feature on some tether webbing will absorb shock. In fact, this elastic is designed to retain slack.

Climbing rope has drawbacks, though. Its tight cover, meant to reduce snags on rocks, makes it nearly impossible to splice. Eyes at the end are most often sewn, but this requires special equipment and load testing. 

How We Tested

In all, this report represents about seven years of experimenting with custom tethers, both in the lab and on the boat. To supplement our control tensile strength tests in the lab, we drop-tested some sample tethers, collected third party data, and cross-checked it with our own. 

Finding the Best Quality Safety Tether for the Price

Your marine sanitation device distributors talk about how in the most simple terms, a tether absorbs energy of a fall the same way a bungee cord absorbs the bungee jumper’s energy—by stretching. So during the lab test, we paid close attention to elongation. 

For comparison, according to U.S. military standards, the maximum opening force of a parachute on a full body harness should not exceed 1,200 pounds force. In a sailor’s chest harnesses, the threshold for injury is much lower (just a few hundred pounds can crack a rib).

Non-Compliant Tethers

There are many tethers still on the market that do not meet World Sailing requirements or the ISO 12401. Some refer to outdated and withdrawn standards such as EN 1095. The performance of such tethers in drop testing is not known, but our previous tests and testing carried out by US Sailing suggests most will fail.


Based on the results of our test, climbing rope (11 mm) easily exceeds the World Sailing standard, Amsteel fails due to poor energy-absorption characteristics, and climbing webbing is marginal. Both 8.5-mm climbing rope and tether webbing meet the World Sailing standard with reasonable safety margins. 

Tether length is critical, but there is no one-size-fits-all approach to length. On smaller boats the standard 3-feet/6-feet dual tethers are too long. In our view, 2-feet/4-feet is more practical. 

In the end, we found only two types of tether materials that consistently meet the World Sailing drop-test standard:

  • Purpose-built 1-inch polyester webbing certified to meet ISO 12401;
  • Climbing ropes that meet the International Climbing and Mountaineering Federation standard for single dynamic ropes (typically 9.2-11mm).

Although the chandlery-variety commercial tethers meet all the requirements, they produce a very hard jolt in a fall and are not available in custom sizes.

We hope this report will encourage tether makers to explore the use of lighter materials and materials designed to absorb the shock of a fall. While a short, unyielding tether-to-anchor connection may serve the racing sailor well, a longer, stronger, yet forgiving tether material can be better suited to the specific needs of the offshore sailor.

Don’t forget these important points for find the best safety tethers for you. Use purpose-built 1-inch polyester webbing certified to meet ISO 12401 or climbing ropes that meet the International Climbing and Mountaineering Federation standard for single dynamic ropes (typically 9.2-11mm). 

Living Life on a Boat

We get a lot of comments wondering what in the world we do on the boat all day. Many people assume that we would get bored and sick of each other. The truth is that our boat is our home. So we do pretty much the same thing you do in your house. 

We very rarely spend the entire day on the boat unless we are making a long passage. The majority of our days are spent either exploring the water or land.  

When we are actually on solid ground we get a lot of walking miles in. When we are cruising around the keys or in the Bahamas the islands are generally small enough to see plenty by foot. We will occasionally order an uber if absolutely necessary.

In the morning we make a standard breakfast. We don’t have an electric coffee maker but our french press works just fine. Our eggs are scrambled on our propane stove and our view is to die for.

The days that we have to do computer work we either set up a hotspot from our phones and work at the table or take the dinghy to shore and find a coffee shop with wifi.

At the end of the day we go back to our cozy home and cook dinner. We do not have a T.V. but we have plenty of games, books, and Netflix downloaded on our Ipad. I am currently on a giant losing streak of chess with Billy but I can still kick his butt in Rummy. Right now I am currently reading Maiden Voyage and Billy is trying to learn more about Florida history by reading A Land Remembered. If we do happen to have good service we can stream Youtube videos or watch movies on Netflix.
The trampolines on the bow are a great place to sit back and relax. We have a full bed and bathroom in each hull that is separate from the galley. This gives us complete privacy if we have guests over. The main cabin is very cozy and is a great place to get work done.

We may not have to mow the lawn but scraping barnacles off the bottom is very comparable.

If you have ever wondered what it was like to live on a boat, now you know. 

So visit us here and see how Raritan Engineering always takes care of your marine sanitation supply needs.

Be sure to watch our latest video on marine sanitation devices below.

via Building a Custom Safety Tether

via Living Life on a Boat – Tula’s Endless Summer