Use anchor drag bearings for worry-free anchoring
by John Jamieson/Sail-World Cruising on 29 Jan 2012
Anchoring, when you are close to shore, rocks or coral, has often been said by wise cruising sailors to be more dangerous than a stormy ocean. You lower your boat anchor, set it deep into the seabed, and neaten up the deck. But how do you know your anchor will not drag when the wind shifts? Better put these five sailing tips into play to make sure your hook--stays put!
Anchor check at sunset .. .
No matter what you've read about the biggest, baddest anchor in the world that can hold the Queen Mary in a full November gale, anchoring remains a risky venture with many variables. Assume your anchor will drag and plan for it.
This defensive mindset could save you from becoming an insurance statistic. Several years ago, I crewed aboard a boat that dragged in a freak summer gale and plowed into a rock seawall. It sank to the spreaders within twenty minutes. We barely escaped with our lives; fortunate indeed that no one was injured.
While the type of anchor you choose can make a world of difference to how secure your boat is, any anchor can be made to drag. Boats at anchor bob up and down or shear from side to side. Wind, sea waves, swell, passing boat wakes, tidal rise and fall and current all combine against your anchor. If the wind or current shifts in a different direction, side loads are placed onto the anchor shank (long arm), which increases drag potential.
Imagine a tie around your neck. Grab the bottom of the tie, then pull and release the tension on the tie over and over again. That's similar to what happens to your anchor ground tackle each moment you are at anchor.
If the anchor breaks out of the bottom, your boat could drift into another boat or onto a shoal. Use drag bearings as the primary defensive strategy to know if you are dragging. Follow these five ways for peace-of-mind:
1. Put out the total amount of anchor scope necessary for your anchorage spot. Wait a minute or two for your boat to settle down.
2. Look off the port or starboard beam of the boat. Find two objects that form a line--or 'range'--on or near the shore. For example, a tall piling on a pier that lines up with a large tree or a flagpole that lines up with the corner of a roof.
3. Some isolated anchorages might have just one visible object, such as a distant hill or house. Shoot a bearing to the object with a hand-bearing compass.
4. Record the drag bearing objects or object in the boat log. If you use a compass bearing, write the compass bearing in a separate column adjacent to the object. Pass this on to your sailing crew or partner so that all hands know what drag bearings are being used.
5. Check for wind or current shifts. Choose new objects in range or shoot a new drag bearing if your bow changes direction. Record the bearing and objects in the boat log as described above. Communicate this to your crew.
6. Backup Drag Bearings with Electronic Wizardry: Set your gps or chart plotter proximity waypoint function. This feature allows you to set a 'circle of protection' around your boat in yards or tenths of a mile. If you drift onto the edge of the circle, an alarm will sound.
7. Use radar in a similar fashion. Choose a point of land or object ahead of the heading flash (which represents your bow). Use the VRM (variable range marker) to determine the range to the object or landmass ahead of the boat. If the boat starts to drag downwind, this range will change.
Realize that electronics may be in error by several yards, so these should be used as a backup to the visual methods described earlier. Always use at least one backup method of sailing navigation with electronic navigation.
Use these easy anchoring tips each and every time you anchor. You will sleep better at night when you know that your boat anchor will hold your cruising sailboat in place--wherever in the world you choose to cruise!
John Jamieson (Captain John) with 25+ years of experience shows you the no-nonsense cruising skills you need beyond sailing school. Visit his website for a free sailing tips newsletter. Become a member for instant access to 500+ sailing articles, 90+ sailing instructional videos, 135+ sailing newsletters, sailing topic e-Books, and live discussion forums.
If you want to link to this article then please use this URL: www.sail-world.com/93345