Thanks to a good catch by Marty S. I have corrected an error in the Anchoring Scope and Swing Radius spreadsheet on the Downloads page. The 5:1 radius was not calculating in yards, but in feet. We rarely use more than 3:1 with New Morning's 55kg Rocna so I never noticed the error.
The question was also been raised about why the spreadsheet uses yards instead of feet since most US boaters think of the length of their boat in feet (though everywhere else in the world they think of it in meters). The reason is that when anchoring I use a Bushnell laser rangefinder to measure distances to swing obstacles. My first year of cruising I found that I significantly under-estimated distances so I bought a rangefinder designed for golfers to measure the distances objectively. The rangefinder reads out in yards (or meters). When anchoring I use this to measure the distance to other boats, moorings, marked ledges/reefs, etc. Using the spreadsheet (I keep a copy in a plastic cover in the cockpit) and the rangefinder simplifies the process of determining exactly where/when to drop the hook.
