The Weakest Links

We’ve all heard the expression “a chain is only as strong as its weakest link.” When it comes to boating safety, a few items on your boat come to mind that fall under the “weakest link” theory. How about anchor lines, mooring lines and mast stays, just to name a few?

A failure of a “chain plate” on a sailboat will probably lead to a falling mast! For you land lubbers and power-boaters, let’s start by explaining what a “chain plate” is. Chain plates are bolted to the side of a sailing vessel and provide a connecting point for the stays that hold the mast in position.

Most chain plates look like a short piece of flat-bar that is bolted to the side of the vessel at one end and to the mast stays at the other end. On some vessels they are visible on the exterior of the hull while others may pass through the deck and bolt to an internal attachment point.

The term “chain plate” comes from the days when a short length of chain was attached to the plate (chain plate) and the “deadeyes” (tackles) that held the mast stays in place were fastened to the other end of the chain. The chain allowed the particular stay to move in any direction so it performed as a universal joint. Today we accomplish this universal joint action with a “toggle”, a device that has two holes at right angles to each other and allows the stay to move fore and aft as well as laterally. The term “chain plate “has lived on.

You might imagine what happens on a sailboat if a chain plate comes loose or otherwise fails. It doesn’t take much of an imagination to visualize the mast tumbling down. The incident will be without warning since the deterioration may not visible to the boat’s operator.

Did you ever go to sleep in a safe inland anchorage and wake up a few miles offshore? If so, it could be due to “chafing” (wear or abrasion) on your anchor rode. The more chafing, the weaker the link!

If you are inclined to be a Good Samaritan in the case of a fellow boater without a TowBOAT/US membership, you might call on your anchor rode for help. Your anchor line is likely to be the longest and heaviest line on your vessel. The chance of chafing during towing is even much greater than when anchored.

When at your dock in heavy weather, your mooring lines may have occasion to chafe or be subject to repeated shock loading. If you have a few worn parts of a line, it may part after a prolonged strain. That event will allow your vessel to move against a dock or bulkhead and risk some damage.

In all of the previous examples, the problems can be avoided through routine inspection. It follows that we should do a thorough visual inspection of anything that has the potential of being the weakest link in the chain.

It makes good sense to have a maintenance schedule. It should include not only oil changes, replacing filters, etc., but also visual inspection of hardware, wiring, lines and anything else that might give out on you one day. You’ll be glad you did!

Until next time, we wish you clear skies, fair winds and calm seas!


World Wide Marine Training, LLC, is a U.S. Coast Guard Approved facility authorized to give examinations for captain’s licenses up to Master 200 Tons, Able Seaman up to Unlimited, STCW Basic Training, Radar, ARPA and other Endorsements. Please visit or call toll-free 866-249-2135.