Small Versus Large Anchors


The consensus among anchor makers (Fortress, Bruce, Manson, Mantus) is that holding power in soft bottoms increases in approximate proportion with anchor mass; exponents range from 0.92 to 1.0. While there are differences between models and manufacturers, a 35-pound Mantus should hold roughly 18 times more than a 2-pound Mantus, and a Fortress FX-16 should hold four times more than a Guardian G5.


If we compare our soft mud 2.5-pound Mantus holding result (35 pounds) with the 45-pound Mantus result (750 pounds), the scale-up error is about 20 percent. The same is true for the Guardian/Fortress comparison and the Claw comparison: about 20-percent scale-up error. The drag-in distance to full holding was proportional to the anchors physical size, a trend supported by U.S. Navy testing; Anchors tested at Solomons Island took 30 to 40 feet to develop full hold, while the small anchors took 4 to 10 feet. These are averages; variations between runs were often 50 percent or more, often due to trash in the mud.

Overall, the burying behavior, turning behavior, and relative holding power of the pint-sized anchors in consistent sand and soft mud is consistently proportional to full-size anchors. In other bottoms, especially those that are hard to penetrate, the results are less comparable.

Practical Sailor has been independently testing and reporting on marine products for serious sailors for more than 45 years. Supported entirely by subscribers, Practical Sailor accepts no advertising or any form of compensation from manufacturers whose products we test. Testing is carried out by a team of experts from a wide range of fields including marine electronics, marine safety, marine surveying, sailboat rigging, sailmaking, engineering, ocean sailing, sailboat racing, and sailboat construction and design. This diversity of expertise allows us to carry out in-depth, objective evaluation of virtually every product available to serious sailors. Practical Sailor is edited by Darrell Nicholson, a long-time liveaboard sailor and trans-Pacific cruiser with more than three decades of experience as a marine writer, photographer, boat captain, and product tester. Before taking on the editor’s position at Practical Sailor, Darrell was the editor of Offshore magazine, a boating-lifestyle magazine serving the New England area. Darrell has won multiple awards from Boating Writer’s International, including the Monk Farnham award for editorial excellence. He holds a U.S. Coast Guard 100-ton Master license and has worked as a harbor pilot and skippered a variety of commercial charter boats.


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