8/16/99 | Anchor stories

storm in chesapeake city

To judge from most of the cruising literature, the activity which generates the most drama and excitement on a boat isn't sailing -- it's anchoring. We were feeling like we missed out, since our ground tackle has performed in a perfectly workman-like manner (other than inadvertently dredging up some huge hunks of mud from the bottom), until a few recent incidents reminded us not to take it for granted.

We arrived in Chesapeake City on the C&D Canal late in the afternoon of Friday the 13th. The only place where it's possible to anchor is the city anchorage basin just off the canal, and there were lots of boats there already. After some discussion, we chose a spot in the far corner. We always try to put out more than 5:1 scope (we let out a length of chain at least five times the water depth), but because of the tight quarters, we only put out about 4:1. (For an all-chain anchor rode, like we use, 3:1 is considered a minimum, but we like to be conservative.) At the north end of our leash, we were fairly close to some government docks, and at another angle of swing we were even closer -- maybe 50 feet -- to some large pilings just in front of the rock-edged east side of the basin. South of us was a small sailboat which appeared abandoned, and a powerboat, the Michele M, just west of the sailboat.

The next day was a hot one, and we put up our awnings before dinghying to town to explore. In the afternoon, we stopped at a bar for a few cold beers and a dose of air conditioning. The bartender turned on the Weather Channel as we drank:  a cold front was moving through the area and storms were expected. She looked out the window and commented, "It's getting awfully dark out there. Looks like it's going to hit soon."

We finished our drinks and quickly headed out to our dinghy. Just as we headed into the anchorage basin, the first gust hit. The fabric of our sunshades rippled and filled tautly in the wind, acting like big sails to push Windom around. As soon as we arrived at our boat, we sprang into action, taking down the awnings as fast as we could. It was quite a task, with the wind fighting us at every turn. The big tent-like sunshade flapped in our faces and billowed into our legs, threatening to knock us overboard.

While we worked, we noticed that the Michele M had dragged its anchor and been swept into the abandoned-looking sailboat. The powerful west wind pushed both boats into the pilings at the east end of the basin. The sailboat Tenacity, anchored a bit farther west, failed to live up to its name, but before it dragged into any other boats its owners arrived by dinghy, jumped aboard, and powered up to re-anchor. One after another, nearly every boat in the anchor basin lost its grip on the bottom and dragged. The basin was a mad scene of boats anchoring and re-anchoring everywhere, with a few powerboats just giving up and holding their positions by just powering into the wind. The owners of the Michele M finally showed up and rescued their boat; no sooner did they re-anchor than another powerboat dragged into them. The old sailboat was recovered and re-anchored by the town's rescue service.

As we stowed our awnings, we kept a wary eye on the pilings behind us, but they didn't seem to be getting any closer. Our anchor was doing its job! We also prepared to dodge any boats coming down on us, but fortunately none did. When it finally occurred to us to switch on our instruments to measure the windspeed, the worst was over, but we still measured steady winds over 30 knots, with a peak gust of 37 knots (over 42 mph).

Why did we stay put, when almost everyone was dragging? Probably there are several reasons. First, we have a type of anchor (CQR, or more generically a plow-type anchor) which is well suited to the muddy bottoms in the Chesapeake. It buries well in the bottom, and if changing current or wind conditions swing the boat, it will turn and reset while still buried, rather than pulling out. (This surely helped us, as we anchored to a southeast wind, but the squall brought gusts from the west.) Although we couldn't tell what kind of anchor everyone else was using, two boats which dragged and re-anchored were using Danforth-style anchors. We also noted that most of the other boats used nylon rode rather than chain; to hold well, this kind of anchor line must be set with greater scope, typically 7:1, and in these tight quarters, no doubt many let out much less line than required. Finally, we always set the anchor "by the book": Britt lets chain out slowly while I back down at low RPM, then Britt locks down the rode and watches it for tension while I give it a little more power to set the anchor, and then finally I slowly increase the RPM to test the anchor set. If it doesn't budge with 50 horsepower yanking on it, we know it's really buried. But we've seen lots of boats, particularly those powerboats where a cockpit switch controls the anchor (rather than a person on the bow), simply release the anchor and call it good.

tide surprises

The following night we anchored in the Delaware River off of the town of New Castle, Delaware. There wasn't much for an anchorage, but the wind was fairly light and blowing from the northwest, so the shore would protect us. As we approached the shore, the water remained fairly deep, which was a concern since deeper water means more anchor chain out, which means more swinging room, but it soon started to get shallower. We debated about what depth to drop the hook, and finally decided that since shifting currents or winds might swing us toward shore, 11 feet would be a good depth. (We had calibrated the depthsounder so that it now read true depth, so 11 feet meant a little less than 6 feet of water under our keel.) This turned out to be a very good decision, but for completely different reasons.

We'd ridden a fast and favorable current up from the exit of the C&D Canal, which in itself was rather weird -- the Delaware was flowing "backwards"! The current was so strong that Windom sat to the current rather than toward the wind, with its bow pointing into the current. We dinghied ashore, tying up at the edge of the old ferry wharf, and when we returned a few hours later we could see our boat pointed in the opposite direction. The tide was going out with a vengeance; our dinghy was nearly aground, and we needed to recruit a bystander to help us get refloated so we could get back.

It had surprised us to see our dinghy aground. After all, the tidal range in the Chesapeake is only a bit more than a foot in most places, two feet at most. When we got back on our boat, we turned on the depthsounder to discover that the depth had dropped to about 8.5 feet.

The main reason we went to New Castle was because there's a marine store there, and we wanted a cruising guide for the Delaware and the New Jersey coast to supplement our charts, since the guidebook we had only covered the Chesapeake. We glanced through our new guidebook as we drank our evening cocktails, and learned a very important fact: the tidal range on the Delaware is five and a half feet.

Uh-oh. I checked the depth again:  7 feet. We had tide tables for the Chesapeake, but not for the Delaware. Every so often during the evening I'd glance at the depth. 6.5. 6.2. 5.9. Were we going to ground?

Finally we found a clue in the guidebook:  the tides at the western entrance of the canal were two hours behind Elkton, MD, we had the Elkton correction for the Bay tables, and we weren't too far north of the canal. At what we figured was around low tide, the depth was 5.7 feet. Not much clearance for our 5'1" draft, but it would do.

We were lucky to get through this incident with no more difficulty than a temporarily-stuck dinghy. It was a good wake-up call for us to pay attention to the tides when anchoring -- not only because a falling tide might leave us aground, but also because a rising tide changes the ratio of anchor rode to water depth, and might make our ground tackle ineffective. (If we'd anchored at low rather than at high tide, our depth at high tide would have been around 17 feet. The 75 feet of chain we had out was almost 7:1 scope at 11 feet, but would have been less than 5:1 at 17 feet.) This also reminded us not to make assumptions -- just because the Delaware is near the Chesapeake, there's no reason to expect them to have similar tidal patterns (and they don't!).