Help,
I wanted to see if anyone can give me an idea of how much weight (concrete) for mooring I should place in 9-11' (Low-High Tide) of water for a hunter 25 (4400lbs).
Thanks!!
What is the bottom type?
Many municipaities have studied this and some have come up with minimum requirements for dead-weight moorings. To meet the bare minimum dead weight mooringrequirement for the town of say Rockport, MA, for a 25 footer, you'd need a dry weight cement mooring of 2750 pounds to hit the 1500 pound minimum for a submerged concrete mooring.
Below are some mooring guidelines, this one from Rockport, MA, that we use up here in the North East. These are minimum safe weights..
Dead-weight Anchors:
"Dead-weight anchors are commonly used in New England. They are usually blocks of granite which hold vessels in place because they are too heavy to be dragged or lifted by the vessel. The holding power of the dead-weight anchor is derived solely from it's weight and not by its design. When a dead-weight is pulled out of its current resting place, it may settle somewhere else, because its weight provides constant resistance. Blocks become embedded in the harbor bottoms over the years, providing a degree of suction resistance in bottom material which has strong cohesive properties. Thus, a dead-weight anchor is not likely to break free from its set like a mushroom anchor. (An anchor is "set" when it becomes buried in the harbor bottom over time.)
It is recommended that the weights indicated be submerged weight of the dead-weight anchor. Use the following table to calculate required weight of material submerged. Consult with the Harbormaster before purchasing gear.
Minimum dead-weight mooring weight:
Vessel length:
Suggested Submerged Minimum
10 - 17 1000 lbs.
18 - 26 1500 lbs.
27 - 35 3000 lbs.
36 - 45 4000 lbs.
45 - 55 5000 lbs.
Submerged Weight Calculations
Concrete = required weight /.55 (example 1000 lbs./.55 = 1818 lbs.)
Granite = required weight /.65"
