Ø … Upgrade or downgrade my ground tackle? The difference between upgrade or downgrade may have more to do with how and where you use your ground tackle than the size/weight and type/brand of anchor.
Two books cover the art and science or anchoring very well. Earl Hinz’s book: The Complete book on Anchoring and Mooring is an excellent guide that I carry onboard whenever I cruise outside of my home waters. If you want to delve deeper into the dynamic forces involved with anchoring William Van Dorn’s Oceanography and Seamanship is the overkill read. If a boat typically anchors in known waters with good holding and reliable shelter (calm seas, low current etc.) using the “light” end of the anchor manufacturer’s recommendations seems fine, especially on lower displacement boats without a windlass. To help sleep soundly at anchor, especially if the weather conditions or holding ground are less than reliable, having the ability to add chain or a kellet can significantly add to any anchor’s holding power. Carrying and extra anchor or a different type (Danforth type especially the Fortress brand make great back up anchors when storage is tight) gives some flexibility if the primary anchor will not set. Calypso displaces 24,000lbs and has a lot of windage, the anchor roller is approx. 5 feet off the water, and she will buck enough in a rough anchorage to add significantly to the dynamic load on the ground tackle. I cruise in the PNW where, especially in British Columbia common anchorages might be 30 to 60 feet deep with a 10 to 15 foot tidal range. I went into overkill mode when putting together Calypso’s primary ground tackle. Our non-racing anchor is a 65lb CQR (20lbs heavier than the recommendation) with 90 feet of chain and 300 feet of rode. We do have an oversized Lewmar windlass and the battery to support it. I carry a spare normal sized Danforth and a smaller Danforth as a stern anchor. When cruising in remote or unfamiliar areas I will add an anchor buoy to help mark the anchor’s position and help in retrieving in case the anchor fouls. I use a wide range of scope lengths depending on many factors. The PNW tidal range, wind/sea/current conditions, how crowded the anchorage is, etc. all factor into my scope guesstimate. How well the anchor sets and holds confirms how well I guessed. We also stern tie quite often which deserves its own discussion. In sum, if you know the anchorage well, the weather is settled, and the anchor set well I bet using the manufacturer’s recommendation will work out fine. Martin DeYoung Calypso 1971 C&C 43 Seattle [Description: Description: Description: Description: cid:D1BF9853-22F7-47FB-86F2-4115CE0BAF2F] From: CnC-List [mailto:cnc-list-boun...@cnc-list.com] On Behalf Of Robert Hrabinsky via CnC-List Sent: Tuesday, May 05, 2015 8:39 PM To: Jean-Francois J Rivard via CnC-List Cc: Robert Hrabinsky Subject: Stus-List Did I upgrade or downgrade my ground tackle? My C&C 30 MKII displaces about 8,700 lbs unladen. I just replaced my 33lb Bruce with a 22lb Rocna. The question is: Am I an idiot? The Rocna sizing chart suggests a 15kg (33lb) anchor for my displacement, but the website goes on and on about how conservative their ratings are. It looks like a 10kg (22lb) Rocna would be recommended for a 30ft boat displacing 7k or less. I would have gone for a larger Rocna, but it wouldn't fit (the shank is too long). My reasoning is that the 22lb Rocna will almost certainly outperform the 33lb Bruce. What say you? Rob H. Sent from my Samsung device
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