We are Great Lakes cruisers, learning how to cruise The Bahamas. Most anchorages here experience tidal flow, with the boats shifting from one end of their anchor perimeter to the other. Though there normally is wind, the boat usually doesn't "swing" around the perimeter, with a taught rode. I have watched us slowly drift directly over the anchor as the tide switched.
Two nights ago this resulted in a wrap around our keel. We have a 1995 C36 with a wing keel. We didn't discover the wrap until early morning. It was blowing hard. The wrap was tight. 40+ knots of wind were forecast to arrive in 6 hours from a new and unprotected direction. Slack water would not arrive for two. We couldn't wait that long. I had to cut my brand new Mantus free. The rode is on a float, and I hope to return and retrieve the anchor in two days, when the wind abates. We tucked into a marina to hide from the blow.
I need to learn:
- How to avoid keel wrap, and
- How to undo a keel wrap.
Here are my initial thoughts. I'm looking for corrections to any misunderstandings I have, plus any and all additional suggestions.
1. So, how to avoid keel wrap? I have (or, hope to soon again have) 70' of chain and about 200' of nylon 8 plait. We were anchored in about 14' at low tide, which is fairly deep for an anchorage around here. High tide added about another 3'; I estimate my bow at 4' above waterline. Because of the high winds we were experiencing (upper 20's, gusts into the mid 30's) I set out a lot of scope, about 210', which gave me a 10:1 scope.
I think the solution is to keep the rode hanging down vertically from the bow roller, when it's not under tension.
a. Probably the most obvious solution is to add more chain. If I'm anchoring on all chain, even with a nylon bridle set up, the chain weight should keep the rode straight up and down. The problem with this solution is cost, given where I am. I had to buy additional Racor spin on filters while here, because of a load of bad fuel we took on. They were $48.00, each.
b. My next thought is to add a kellet, putting it out a distance somewhere between my draft of 4'5" and the bottom we are anchored to (anywhere from 6'+). I think that I don't want the kellet to drag on the bottom. There's too much it can get caught on. This should allow the rode to go vertical when it's slack.
2. How to undo a keel wrap? With the addendum: and not wrap the d**n rode around the propellor?
a. Given the option of waiting for slack water, I anticipate I'll be able to dive and physically unwrap the rode.
b. Reduce rode tension? We've all had to unload a winch to undo an override. I suppose I could try to attach a separate line to the rode and haul that in to create slack. The challenge will be attaching the line at a depth of probably 6'-10', likely with a current running.
c. Power up and turn the boat to unwrap the rode? This option seems fraught with additional peril. But, here's where I lack experience. If I were to try it, I think I would have my snorkel and mask on, step down the aft ladder, watch what was happening under the boat, and relay instructions to the Admiral at the wheel.
I apologize for the length of this entry. I'm still in the moment, and it was all-encompassing for a few hours.
1995 C36, tall rig, wing keel