Possibly the anchor chain caught under a larger coral head right under the bow so that in effect there was 1:1 scope. If it was blowing 40kn across a coupe of miles of fetch then the sea might have been three or four feet. Coming up short like that would put a huge strain on the chain and windlass, as I believe the snubber had already gone. I would have thought that the brake on the windlass would slip before the chain broke. Of course the chain is only as good as the weakest link.
I think the morals of that story are:
1. To always snorkel your anchor in coral waters, and re anchor if need be.
2. Have a second anchor ready to go.
3. Have a really long snubber of nylon that will stretch and can be let out as the wind builds.
This all brings us back to an earlier discussion about tandem anchors. In this instance in Suvorov it would not have helped. Two separate anchors and cables would have saved the boat.
On my first boat I sat out a gale at the Club Med Motu in Bora Bora in 1991, there were quite a few yachts in the anchorage, maybe 10. We had just sailed in from Raiatea and by dusk, having snorkelled the area I decided to lay a second anchor at 45 degrees to the first. The night started with SE 25kn and gradually veered to the South and SW peeking at 60 kn in the gusts. Two yachts were wrecked that night. My boat was only 35 ft. I could row out anchors by hand quite easily.
With a big Amel anchor of 40kg it is still possible but harder. I have had good results using a couple of fenders slipped through the anchor itself and towing it with a load of chain and rope in the dinghy, then letting slip when the anchor is positioned. Not easy when it gets rough!
Nick ( Amelia)
I believe that rather than morbid curiosity, the original reason to post this tragedy was because Bill R had asked if anyone had ever heard of an anchor chain breaking. The listing for Makoko suggests they had 70 m of 12mm chain with a Spade Anchor. The Kiwi article says that their anchor chain broke in 35-40 knots of wind. Ian, I did find a subsequent reference on another blog of the same owners as in the article calling the boat Makoko as you had suggested. I suspect they had just renamed her prior to this. It's very sad.
Future SM2K Owner