TL;DR
When an anchor drags, I look at four things in order: the bottom it is sitting in, how much rode is out for the depth, whether it was actually set under power, and whether the anchor and rode suit the yacht. Choose good holding ground, let out generous scope, back down slowly until the yacht stops, then confirm with transits or an anchor alarm. If it drags again, re-anchor early rather than hoping.
Some of the calmest evenings I have spent on the water have been at anchor, and some of the least calm began the same way. The difference is almost never luck. When an anchor drags, it is telling you something specific about the bottom, the scope, the set or the gear, and each of those can be checked before the wind picks up rather than after.
Start with safety
If the yacht is already moving toward a hazard, a lee shore, another vessel or shallow water, stop diagnosing. Start the engines, keep people clear of the bow and the moving chain, and either re-anchor or leave. Fingers and feet do not belong near a windlass under load. Diagnosis is for later, when the yacht is safe.
Step 1: Consider the bottom
Holding ground matters more than most owners expect. Firm sand and good mud generally give an anchor something to bite into. Weed, grass, loose shell, soft silt and rock can let an anchor sit on top, skip, or hook on something that later lets go. Your chart often notes the bottom type, and local knowledge is worth asking for. In clear water, I look before I drop. In many protected areas, anchoring on seagrass or coral is restricted or prohibited, so check the local rules for where you are and use mooring buoys where they are provided.
Step 2: Check your scope
Scope is the ratio of rode let out to the depth plus the height of the bow above the water. Too little scope pulls up on the anchor rather than along the bottom, and an anchor pulled upward will break out. I always add the bow height and allow for the tide before I decide how much to let out. As a general guide many captains work with more scope for rope than for all-chain rode, and more again as the wind rises, but the right figure depends on your gear, the bottom and the forecast. When in doubt, and when swing room allows, more is kinder.
Step 3: Set it properly, every time
An anchor that has been dropped is not the same as an anchor that has been set. This is the step I see skipped most often. My routine is simple:
- Come to a stop at the spot you want the anchor, heading into the wind or current.
- Lower, do not drop in a pile. Pay out rode as the yacht drifts back so the chain lies along the bottom rather than on top of the anchor.
- Snub gently once a good length is out, to let the anchor start to dig in.
- Back down slowly, increasing power gradually. Watch a pair of fixed objects on shore that line up, or the chartplotter position. When the yacht stops moving under steady reverse, the anchor is set.
- Rig a snubber or bridle on an all-chain rode, so shock loads are taken by nylon rather than by the windlass.
Step 4: Allow for the swing
Many “dragging” alarms are not dragging at all. The yacht swings with wind and tide around a circle roughly as wide as the rode you have out. Before I settle in, I note the anchor position, set an anchor alarm with a radius that allows for the swing, and look at what else is in that circle: other yachts on different rode, shallows on a falling tide, moorings. A wind shift overnight can turn a comfortable spot into a tight one.
Step 5: Look honestly at the gear
If the bottom is good, the scope is generous and the set was done well, and the anchor still drags, the gear deserves a look. Is the anchor sized for the yacht’s displacement and windage, by the manufacturer’s own guidance rather than its weight alone? Is the chain the right size for the gypsy, and is it marked so you actually know how much is out? Check the shackle, swivel and mousing, and look for a bent shank or worn galvanizing. A yacht that has been upgraded or re-rigged over the years sometimes ends up with an anchor chosen for a different boat.
Step 6: When it drags anyway
Re-anchor early. The first time an anchor drags is a polite warning; waiting to see whether it will hold again rarely ends well, and it usually happens at night. Pick up, look at what came up on the flukes (weed and clay tell you a great deal), choose a better patch, and set again. If conditions are building and the anchorage is open to them, the best answer may be a marina or a more protected bay. There is no shame in moving; I have done it many times.
Frequently asked questions
How much anchor rode should I let out?
It depends on depth, bow height, tide, the bottom, your rode type and the forecast. Measure from the bow, not the waterline, allow for high tide, and let out more as the wind rises if your swing room allows. Your anchor and windlass manufacturers’ guidance is a good starting point.
How do I know my anchor is set?
Back down slowly under steady reverse and watch two fixed objects on shore that line up, or your chartplotter position. When the yacht stops moving and stays stopped, the anchor is set. Then set an anchor alarm and check again after the first wind or tide change.
Is a bigger anchor always better?
Not always, but an undersized anchor is a common cause of dragging. Size it for your yacht’s length, displacement and windage using the manufacturer’s guidance, and make sure the chain, shackles and windlass suit it as a system.
Captain JC — Juan Carlos Castro II. USCG 200-Ton Master · 500-Ton ITC · English & Español. About Captain JC
This article is general guidance from one captain’s experience, not a substitute for your surveyor, insurer or the U.S. Coast Guard. Rules and requirements change; verify current ones before you rely on them.
