Came across this article with sound advice on marking your boat’s anchor rode.

On today’s boats, electronic depth sounders have largely replaced leadsmen calling out the depth in fathoms, as related in Mark Twain’s “Life on the Mississippi.” But for anchoring, a traditional technology is still the best trick. That technology?

Simply marking your boat’s anchor rode at regular intervals.

Scope It Out

Successful anchoring heavily depends on scope: the ratio of anchor rode to water depth. A good baseline is to put out 5 feet of anchor rode for every foot of water depth. We’d call that a scope of 5-to-1.

Water depth for anchoring is calculated from the seafloor to the anchor roller or chock at the top of the bow, which is usually several feet more than the depth sounder’s reading. More is always better, as a rule of thumb, providing there’s room to allow for the boat to swing.

For a quick stop in benign conditions, including a good-holding bottom, you can use a little less scope, say 3-to-1. In rough conditions or for times you’ll be away from the boat, you need more scope: perhaps 7-to-1, assuming the anchorage provides ample room for your boat to swing, considering shallow water, obstructions. Many anchor-dragging incidents are caused by putting out too little scope, which doesn’t allow the anchor chain and rode the best angle for digging in and staying in.

Mark It Up

Marking your rode is a quick way to see in real time just how much scope you’re putting out. A typical marking system uses three colors three times each. Start off with one color used once, twice, then three times for each selected length, then the next color, etc. These colors may be from paint common on chain, or they may be made using ribbon more common on rope.

I watched a transatlantic crew spray paint their chain with yellow, blue, and red marks at similar intervals. If you plan to re-galvanize your anchor chain, painted marks may make cleaning, or “pickling,” the chain more difficult.

Another technique is to use colored three-strand line, then braid the strand through five or 10 links of chain at regular intervals. You can use large colored zip ties, leaving the tails intact. If you’re not into doing it yourself, chandleries sell color-coded markers in green, red, yellow for less than $6. These are marked with numerals for depth at 30-foot intervals.

No matter which method you choose, make sure your system passes over the gypsy.