Anchor Sizing

[CGWILSON]

Is there a practical way to determine the size of an anchor required for a vessel dependant on current speed?

[Peter_T]

Either you find a rule book on classing yachts to take advantage of the equipment table, or you can use a direct method to assess the frontal wind/current load with side drag using an oblique windage at 30 degrees from the boat's heading. Often people and Class. omit the drag force from horizontal surfaces. You may added these for adequacy of the hawser system.

Hawsers should be suitable to withstand the severe weather load, if they are intended to face the storm, else, use half the storm intensity as equivalent to severe inland wind and current strength.

Having determined the horizontal hawser load, convert this to fit with the depth of water and the chain scope, using catenary principal. Anchors can be traced for holding power.

Peter

There are too many variables. How good the bottom is would be a key variable. Anchor size is determined by manufacturer's recommendations, which vary with the boat's size. Anchor type depends on the type of bottom. See a West Marine catalog.

Go to http://www.westmarine.com, and find the product advisor section.

People who plan to do serious cruising generally select the next size up from that suggested by manufacturers.

Also, get a copy of "Chapman Piloting: Seamanship & Boat Handling"

Tim Dunn