Acceptable minimum spacing between moored buoys

[floating]

Are there any rules or guidelines for how close buoys can be placed? These are large NDBC-style moored buoys, rather than buoys intended to moor ships. The scenario is multiple adjacent buoys, each with a 3-leg mooring, deployed for a long time (must withstand 100-year storm). I would imagine guidelines would seek to prevent fouling with adjacent buoys or a servicing vessel coming to deploy/inspect/service a buoy in the group. I am also wondering what damage scenario I should assume (1 mooring leg broken, 2 intact?)

If you know of any relevant guidelines (DNV, marine experience) that govern how close buoys can be placed, please let me know.

 

[gonzo]

The spacing depends on the length of the vessels which will be moored.

 

[AndySGray]

These are NDBC-style buoys which are moored, rather than a buoy which ships can moor to. Have updated the original post.

Changes to the original post now makes the original reply (below) seem out of context;-


Remember that even 'Permanent' moorings need to be dived at least annually and thoroughly inspected, also after a storm.

Unfortunately, you can't assume that all boats in a set of moorings will do the same thing, motor vessels with more superstructure and wind-age will head to wind much more and sailing boats (at anchor) will to a greater extent turn into the waves and current.

Local practices vary too, round here we typically tie to a mooring ball using a bridle arrangement and the buoy may be 15 foot ahead of the boat which all adds to the 'swing'.

Contact your local insurance company, they may have their own recommendations - failing to check that could create issues.

 

[JSL]

May be a dumb question but......Are you talking about moored buoys or mooring buoys?

 

[jehardiman]

Get a copy of Buoy Engineering by Berteaux from Woods Hole.

 

[floating]

Buoy which is moored

These are NDBC-style buoys which are moored, rather than a buoy which ships can moor to. Have updated the original post.

 

[Ike]

I suggest you ask the National Data Buoy Center. http://www.ndbc.noaa.gov/

 

[jehardiman]

NDBC deep sea buoys are usually single point moored with watch circles on the order of 1/5 to 1/3 the water depth. And they are not very robust above their needs (a notable function of deep water buoys where the weight of the ground tackle is extreme), many are lost when vessels tie off to them.

Important Notice to Mariners

NATIONAL WEATHER SERVICE SEEKS COOPERATION TO SAFEGUARD CRITICAL DATA BUOYS

The National Weather Service is soliciting the cooperation of the marine community to safeguard offshore automated weather buoys that provide critical information, including wind speed and direction, wave height, pressure changes, and other key data about marine conditions and developing storms along the coast. The data buoys are an integral part of the comprehensive observation system that allows local forecast offices to issue weather warnings and forecasts for the protection of life and property.

Specific steps that mariners can take to safeguard the systems include:
•neither boarding nor tying-up to a data buoy;
•giving the buoy a wide berth to avoid entangling the buoy's mooring or other equipment suspended from the buoy — 500 yards for vessels which are trailing gear, and at least 20 yards for all others;
•reporting to the U.S. Coast Guard any damage you observe to a data buoy;
•reporting to the U.S. Coast Guard any observation of people on or vessels attached to a weather buoy.

The NDBC operates a network of offshore automated weather buoys and Coastal-Marine Automated Network stations that provide hourly reports of marine weather to NWS and other agencies. The buoys, off the U.S. coasts and the Great Lakes, may be nearby or several hundred miles at sea. These stations provide hourly data to NWS forecast offices that are important to the preparation of forecasts and warnings. These data are also broadcast to the public over NOAA Weather Radio, and are posted on the Internet at www.ndbc.noaa.gov.

NDBC buoys have either circular or boat-shaped hulls ranging from three meters to 10 meters across, with superstructures extending five meters to 10 meters above the water. All are painted bright colors and imprinted with "NOAA" and the station number, show a yellow, group-flashing-4 (20 seconds) light characteristic, and are identified on applicable navigation charts by the five-digit station number, or as "ODAS."