Rocna Resetting Failures and evaluation of Vulcan and Mantus

This was a tough article to write back in 2016 when we first published it, and it's a tough one to update, too:

  • It was no fun to reverse ourselves from our long-term recommendation of the Rocna anchor.
  • The article resulted in more angry personal attacks on me than any other we have ever published, at least since we restricted comments to members.

However, we are dealing with a particularly dangerous dragging modality that could result in lost boats, or even lost lives, so publishing, and republishing, this is worth the aggro. Particularly since being aware of the weakness can go a long way to managing it.

Just wanted you to know I don't enjoy calling gear that is much loved by many into question.

With that out of the way, on to the meat of it.

Many of you will be aware of the excellent work Steve of S/V Panope has done by rigging up a waterproof video camera in such a way that it allows the viewer to see exactly how an anchor sets, or not, in the real world.

As part of that testing, Steve subjected each anchor to a true resetting torture test by motoring across the position of the set anchor and coming up on the rode at 180 degrees to the original line of set, in order to simulate what happens in a radical wind-shift.

This part of Steve's testing confirmed that many modern anchors reset amazingly well, even after a radical and sudden pull-angle change.

A Scary Problem

That is, with the exception of the repeated reset failures with the Rocna, which you can see in the video above. To really understand what's going on here, you need to watch the entire 11-minute video.

Real World, Too

That said, given my general scepticism about anchor testing, I probably would not have written on this if it were not for the reports of sudden and inexplicable dragging of Rocna anchors that we have been receiving over the last few years.

Put the two together, and I'm convinced that there's a real problem with the Rocna, and that concern extends to the Manson Supreme, since it is so close in design and Steve's testing shows the same failure.

  1. Introduction
  2. 4 Vital Anchor Selection Criteria and a Review of SPADE
  3. SARCA Excel Anchor—A Real World Test
  4. SPADE, SARCA Excel, or Some Other Anchor?
  5. Rocna Resetting Failures and evaluation of Vulcan and Mantus
  6. Some Thoughts On The Ultra Anchor, Roll Bars and Swivels
  7. Specifying Primary Anchor Size
  8. Kedge (Secondary Anchor)—Recommended Type and Size
  9. Third Anchors, Storm Anchors and Spare Anchors
  10. Anchor Tests—The Good, The Bad, and The Downright Silly
  11. Making Anchor Tests More Meaningful
  12. We Love The Way Our Anchor Drags 
  13. Things to Know About Anchor Chain
  14. Selecting a Chain Grade
  15. Anchor Chain Catenary, When it Matters and When it Doesn’t
  16. Anchoring—Snubbers
  17. Anchor Rode Questions and Answers
  18. Q&A: Hybrid Rope And Chain Anchor Rodes
  19. Anchor Swivels, Just Say No
  20. A Windlass That Makes The Grade
  21. The Perfect Anchor Roller
  22. Install A Wash-down Pump—And Save Money!
  23. Anchoring—Kellets
  24. Anchoring—Chain: Stoppers, Termination and Marking
  25. 20 Tips To Get Anchored and Stay Anchored
  26. Choosing an Anchorage
  27. Choosing a Spot
  28. 15 Steps To Getting Securely Anchored
  29. One Anchor or Two?
  30. Two Anchors Done Right
  31. It’s Often Better to Anchor Than Pick Up a Mooring
  32. Yawing at Anchor, The Theory and The Solution
  33. Yawing at The Anchor, an Alternative Cure
  34. How To Use An Anchor Trip Line
  35. ShoreFasts—Part 1, When to Use Them
  36. ShoreFasts—Part 2, Example Setups Plus Tips and Tricks
  37. ShoreFasts—Part 3, The Gear
  38. Gale And Storm Preparation, At Anchor Or On A Mooring
  39. Storm Preparation, All Chain On Deck
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