Safe at Sea: Safe and secure anchoring
(Editor’s note: The following column is a reprint from the paper of June 13, 2018.)
A few years ago I chartered a sailboat in the Caribbean. The first night out, I anchored near a harbor where our family planned to go scuba diving. That night, the boat dragged on its anchor and in the morning we found ourselves in the middle of the channel leading into the harbor. We anchored again, went diving for the day and when we returned to our boat, it wasn’t there. Nearby sailors pointed out to sea where we spotted our boat. Fortunately we had enough gas in the dinghy to reach and recover it. This began a stressful week of cruising where the anchor sometimes held and sometimes didn’t. We wasted a lot of time looking for permanent moorings or docks to tie up to for the night. I’ve reflected since then on safely and effectively anchoring in different places and conditions. Here are some things to consider when anchoring around Sanibel and Captiva.
– Size of anchor. Ask a marine supplier or other boaters what size anchor they recommend for your boat. You will need room to store or mount it and it must be the right size to hold in the wind, waves and current you expect to encounter.
– Type of anchor. An anchor consists of the “fluke” (the blade-like part) and the “shank” that is used to connect the anchor to the boat. Anchors hold by digging their fluke(s) into the bottom. The two most common anchors are the Danforth and the Plow. The seabed around our barrier islands is sand or grass with some areas of soft mud. The Danforth anchor is light in weight, easily stowed and excellent for anchoring in sand and mud, but in grass or clay it is likely to slide. The Plow is heavier and is normally stowed on a fitting on the bow. It has a shape like a plow that will penetrate weeds, sand and grass.
– The “rode.” The rode is a nautical term for the anchor line. The rode may consist of rope or chain or both. The preferred rope for anchoring is nylon because it will stretch under strain without damage, is easy on the hands and will not rot when stowed away wet. Some anchor rodes have a length of chain at the end near the anchor. The chain will lie more horizontal near the anchor and helps the anchor dig in.
– The “scope.” The scope is the ratio of the length of the rode to the depth of the water. The more horizontal the scope is, the better the holding power of the anchor. In calm conditions, a scope of 5:1 is standard. As wind and sea conditions become more severe, a scope of up to 10:1 is recommended.
– Technique for setting the anchor. Survey the anchorage as you approach for water depth and clearance from other boats, should your boat swing due to changes in wind, tide or current. Approach the anchorage against the wind or current, whichever is stronger. Bring the boat to a standstill. Check to ensure that the anchor is attached to the rode and the rode is attached to the boat. Lower – never throw – the anchor over the bow. Apply a small amount of power in reverse and let the rode out slowly. Be sure the line does not wrap around your legs. When sufficient line is out, take a turn around the bow cleat to set the anchor. When the anchor is firmly set, tie it to the bow cleat with a cleat hitch. If you are unsure of how to tie a cleat hitch, demonstration videos can be found online.
– Retrieving the anchor. Approach the anchor slowly using the engine. Take the line in slowly to avoid fouling it around the propeller or rudder. When directly over the anchor, it should break out easily. If not, snub the rode around the bow cleat and run the boat forward until the force of the boat breaks it loose.
Finally, never anchor a boat from the stern where waves or boat wakes might swamp or sink the boat. A stern anchor may be used as a secondary anchor to keep the boat from swinging as long as the primary anchor keeps the boat facing into the wind and waves.
Bob Orr is a member of America’s Boating Club of Sanibel-Captiva. For more about the chapter and the courses it offers, visit www.sancapboating.club or contact firstname.lastname@example.org or 612-987-2125.