An Expensive Lesson in Boating
I mentioned in my last post that we had trouble retrieving our anchor at the South Santee River anchorage (Mile 420). I thought I might describe this situation in detail for any readers that are boaters or potential boaters in hopes they can avoid the problem.
But before delving into our anchor problem, I should explain the impact of different tidal ranges. On the upper Chesapeake Bay, the tidal change every 6 hours is only about 12 to 18 inches. This means if the water depth at low tide is 8 feet, then the water depth at high tide six hours later will be about 9 to 9.5 feet. The water depth then drops back to 8 feet six hours after that. Because of this relatively small tidal change, the speed of the ingoing and outgoing current is not very strong.
Local Wild Life
However, when the tidal change is much larger, such as the 5 to 6 feet in the South Santee River anchorage, the flow of the current is much stronger. This is because significantly more water must come into an area with a 6 foot tidal change in a six hour period compared to an 18 inch tidal change in the same timeframe. On the Chesapeake Bay, with its very slow current, all anchored boats swing on their anchor based on the wind direction. However, once you get to the part of the ICW below Beaufort, NC, it is not the wind, but the current that determines which direction your boat swings on your anchor. In these areas it is possible to be at anchor and have a strong wind blowing from the stern of your boat forward. This usually makes for a bouncy evening.
Getting back to our anchor problem, when I first poked my head out the companionway hatch that morning, I immediately knew something was wrong. Odyssey was lying across the river with the bow and stern each pointing toward their respective shorelines. Odyssey was not pointing up or down the river in the direction of the current, which means, the current was hitting Odyssey broad side. This cannot be unless there is something wrong with your anchor line.
When I went to the bow to check the anchor, the anchor line was not out in front of the vessel as it usually is, but was running back underneath and tightly against the hull of the boat. Since I had put out about 90 feet of anchor line and chain, the anchor was snug in the seabed somewhere about 50 feet to Odyssey’s stern. I knew what had happened. During the night when the current changed directions, somehow our anchor line did not fall completely to the seabed and was now wrapped around either our keel or our rudder and the strong current was pushing the boat against the anchor line. The anchor line was holding the boat broadside to the current. Although I knew it would not work, I tried to pull up the anchor with our anchor windless and after about three turns the windlass would not move. Between the anchor in the seabed behind us and the strong current, Odyssey was in a vice-like grip.
Day Marker at Low Tide
Some of you are probably thinking, “No problem, just put the boat in reverse and back up past the anchor.” I knew with the current this strong our small sailboat engine would not be able to do this. Also remember the anchor line is running along the bottom of the boat to the anchor behind us. I did not want to take a chance of turning the propeller and catching the anchor line in the propeller. We would then have a much bigger problem.
I flagged down a crabber who was going by in something that looked like a 20-foot Boston Whaler. I asked him to tie a line to his boat and pull our stern around to the other side. He gunned his engine but his engine was not strong enough to pull our boat stern against the current. He wished us luck and sped off.
We had only two other choices; wait until slack tide or call BoatUS towing service. I was pretty sure that when we hit slack tide the anchor line would relax and the windlass could pull it in. We could then get the anchor underneath the boat which would make it possible to dislodge the anchor from the seabed. But I was not 100% sure, and there was another problem to consider.
Mile 420 on the ICW is a pretty remote part of the ICW. It is about 18 miles past Georgetown, SC and about 36 miles to the first place we could hole up from the storm (the Isle of Palms Marina). There are no marina stops in between these two locations. If we waited until slack water which was between 1 P.M. and 2 P.M. to get the anchor up, we would only have about 4 hours of daylight left. It would not be enough time to make it to our planned destination in Charleston. We would have to motor 3 hours back to Georgetown, SC for safe harbor. We really did not want to backtrack.
Isle of Palms Beach
Our other choice was to call BoatUS for help. We had “tow insurance” so no problem right? Well, not quite. BoatUS does not get involved in anchor retrieval. They only cut you loose from the anchor and then tow you back to a harbor. However, for $300 they could come out and help us get free. The wind was already picking up in the morning and we did not want to back track any miles, so we told them to come out.
30 minutes later BoatUS was at our location with a much bigger boat. They attached a line to our stern and it took about 30 seconds to pull our boat off our anchor line and around out of the current’s grip and I was immediately able to pull up the anchor. This did not seem to me like an anchor retrieval situation on their part since they never touched the anchor line. I don’t know if we got hosed by these people, but I was glad to have the anchor back on the boat. I paid them the $300. It must have been the easiest money they ever made.
Since we are going to anchor in many more currents down the waterway, I thought about how I might have prevented this problem in the first place. I called my wife’s brother who is an expert on everything related to boating and asked him how to prevent this from happening again. There is a simple fix. He told me to use a “Sentinel Line” when anchoring in swift currents.
A sentinel line (some people call it a “Messenger Line,”) refers to attaching a weight via a snap-shackle to the anchor line. The weight is allowed to slide down the anchor line to a specified distance. For example, where we were in South Santee River, it is about 10 feet at low tide and about 15 feet at high tide. Assuming your boat deck is about 5 feet above the water, you would need to tie a 20-foot “Sentinel Line” to the weight to make sure it reaches the seabed but does not travel any further. You tie the other end of the sentinel line off on your deck cleat. The point of this weight is to hold your slack anchor line to the seabed when your boat rotates at the current change so it does not get caught in your keel or rudder.
I had a sentinel line and weight already rigged up on Odyssey, but I never thought to use it this way. I was planning to use it as an additional weight to send down the anchor line to the end of the chain to help hold the anchor in place during a real blow.
Anyway this was an expensive lesson in boating for us.
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