Monday, 5 February 2018

20 Knots For 20 Hours, With 20 Tons

Crystal Blues displaces just under 20 metric tons, and I always wondered how our new Rocna 33kg anchor behaved - in soft mud I know it buries deep, but in hard sand with grass just how deep does it bury? The shallow waters here in the Bahamas let me see the answer a few days ago - after 20 hours with 20 knots of wind blowing here at Tilloo Cay.

The answer it seems is not very deep, but we've never dragged, even in sustained winds over 30 knots, gusting to 40 knots. The bottom here is really tough, and once you get the point buried it seems to hold well. In this image the load on the flukes is asymmetric, evidence (I think) of the anchor rotating in the sand as the wind veered through 45 degrees, though I'd welcome comments from others on this.


  1. Hi guys. We have the same anchor and have been sitting through similar winds down at Long Island. We have experience a 360 change in winds a couple times, and the most movement we have seen was approx a 2-3'drag 90 degrees from our original hdg, then another 90 degrees from that hdg. Assumed it was resetting itself a couple times. Never felt it, but could have been asleep. We have bee letting out approx 100' of 3/8 chain in anticipation of strong winds, so likely the chain doing the work most of the time. The deepest we have anchored so far since Dec is 10(ish) feet.

    1. Thanks John,
      Yeah, its a hell of an anchor. Like you we're riding on 100'of 3/8"chain, and sleeping well. Where are you now? We just arrived at current cut on Eleuthera, will go through later this afternoon.


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