South Sound Sailing Society Ship-to-Shore : December 1995

Letters : Making Our Mark(s)

How to make mark anchors

Nothing is forever, certainly not the race buoys. This is the story of how they were replaced.

The old engine block anchors, while great habitat for bottom fish, were awkward to handle. So I designed the 180 lb. concrete plow type anchor. The ‘suction cavity’ and lifting ring are evident. The dory-shaped mold has a sand bottom, shaped to suit, into which the mooring ring was buried prior to casting. The plastic film shown clinging to the cured concrete assured a smooth surface, to reduce the chafe to the mooring line.

Chain would resist chafe, but is expensive and would need to be heavy to provide for rusting. The half inch poly line won’t rust. But it will chafe, so its ends were eye spliced around galvanized thimbles and then moused to half inch galvanized shackles with plastic tape. The real chafe protection is due to a fish net float that provides enough buoyancy to keep the line off the anchor, and the bottom. The oversized shackles and anchor ring take the wear. Finally, a small weight was attached about eight feet below the buoy to keep the line from surfacing.

Loading the anchor was straight forward, or is it downward. On site, at Flapjack Point, the jib halyard was hitched to the mooring warp such that the slack would be taken before the double becket reached the halyard block. The halyard winch did the hoisting and allowed an easy decent to the bottom, in about twenty feet of water. The final act was to snub-up on the warp and tow the anchor to its proper position.

Hopefully the chafe protection is adequate, and the iron sections large enough, to last the useful life for the race marks.

The following are my GPS readings for the race marks, lat/long. The estimated geometric error, satellite angulations, should be 100 feet, more or less. The lord only knows what the SA error was!