Concrete Anchors

Dor-Mor Anchors

Helix Anchors

Dor-Mor Anchors

The Dor-Mor anchor is a patented, pyramidal-shaped anchor that is designed to penetrate the bottom and prevent dragging.  The one-piece cast iron anchor is used to moor boats, large and small buoys, docks, oceanographic equipment, containment booms, nets, aquaculture pens, and much more. These anchors have proven so effective that the US Coast Guard is replacing their concrete sinkers with Dor-Mors!

Dor-Mor anchors are most appropriate for:

• Moving water sites such as rivers and coastal areas
• Where the moorings will be frequently moved
• Mooring scopes of 3:1

Here is how the Dor-Mor anchor compares to two other popular types of anchors in a 3:1 scope mooring

• Approximately 10 times the holding power of a concrete anchor of similar weight
• Approximately 2 times the holding power of a mushroom anchor of similar weight

Here are some of the design attributes that make the Dor-Mor anchor work so well:

• Cast Iron design loses only 14% of its weight in water vs. 45% for concrete
• Large surface area of the pyramid shape has a high suction effect when dragged
• Chain wrap is minimized by the short shank design (as opposed to the long shank of mushroom anchors)
• The large diameter size is designed to accommodate the proper sized shackle for the mooring weight

The Dor-Mor anchor is available in sizes ranging from 15 lbs to 4,000 lbs.  For our Watermark buoys we make the following recommendations:

Dor-Mor anchors may not be the best option when:

• Using extremely short scopes (<2:1)
• The bottom is very rocky
• Concrete anchors are sufficient for applications in small lakes or ponds

If you need to deploy a mooring where a Dor-Mor anchor is not suited, check out Concrete and Helical Anchors, or contact us for more assistance.