Learning how to anchor and choose an anchorage, and within it a place to anchor, was among the most important activities we did while we were cruising. We spent over 80% of our time in harbor, mostly at anchor (occasionally on a mooring ball, and rarely in a slip.) Thus, our ground tackle was (after engine and rigging) our most important equipment. We came to feel very comfortable anchoring, and being at anchor. Anchoring is as much art than science, and here's what we learned.
Our anchoring bible was The Complete Book of Anchoring and Mooring by Earl Hintz, supplemented by a few other books. Our primary bow anchor was a 35lb Delta, with 160' of 3/8" BBB chain spliced to 175' of 5/8" 3-strand nylon--we never felt the need to have an over-sized primary anchor, since the weight of chain (over 200lbs if all of it is out) provides sufficient weight on the bottom. Our secondary bow anchor was a 35lb CQR with 40' of 3/16" chain spliced to 220' of 5/8" 3-strand nylon. Our stern anchor was a 22lb Danforth, with 10' of 3/8" chain attached to 175' of 1/2" braided nylon. We also carried an oversized Fortress (21 lb) with 40' of 3/8" chain and 300" of 5/8" 3-strand nylon for storm conditions, assuming sand or mud in the Caribbean. We also carried a ParaTech sea anchor for riding to in storm conditions.
We routinely used a bridle made of two 35' 5/8" 3-strand nylon lines with rubber stretchers, shackled to a chain hook, as a chain snubber on our primary anchor.
We had a Simpson Lawrence manual windlass, that we greased approximately monthly. A manual windlass was one of the 50 attributes we were looking for when we were shopping for a blue water cruiser. While an electric windlass is certainly a nice convenience, our reading (and experience from other boats) led us to believe that an electric windlass sucks up electricity and will eventually fail--inevitably at crucial moments. Soon after we first anchored in Luperon, Dominican Republic, we barely missed getting sideswiped by a big boat trying to anchor near us, whose electric windlass had jammed. So we (i.e. Bill) cranked away.
Here are the points we considered when choosing an anchorage:
- How long do we plan to be here?
- What are the forecast weather conditions for the period of our stay here?
- If adverse weather were to make this anchorage untenable, can we leave easily and is there a safe alternative anchorage we could get to? Have we written down the compass course and GPS waypoints for getting safely out of this anchorage and into the other one?
- How well is the entrance and anchorage area charted and/or marked?
- What kind of light is needed to safely pick a way through any shoals?
- What kind of hazards are there inside the anchorage (changing currents, rocks/coral heads, shoals, fishing nets/boats, ferries/freighters, mooring balls, crab pots, cables, bottom chains?
- How good is the holding?
- Are there any local weather (wind) conditions or exposure to swells that could make it too rolly, or possibly dangerous?
- How crowded, noisy, dirty, or smelly is it?
- How deep is it?
- What is the tidal range?
- How pretty is it when we sit in the cockpit enjoying the dawn and the dusk?
- How long a dinghy ride is it to shore?
- Is there a decent place to dock the dinghy?
- What amenities/attractions are available on shore?
Once we'd picked an anchorage to stay in, here's how we went about picking a spot and laying the anchor. We prefered to pick a spot when the prevailing wind was in effect, so that other boats were lying behind their anchors. That way we could avoid crossing our anchor rode over someone else's (which would mean they could pull ours out when they departed). In the event it was flat calm, or the wind blowing from a different direction, then we had to evaluate where our spot would put us once the boats already anchored move around. If we had to anchor in a calm, we try to set the anchor towards the direction of the prevailing wind.
- On approach, bring the dinghy up tight behind (if towing it), then start the engine and drop sails.
- From the chart and viewing from a distance, pick a general area to drop the hook in.
- One person goes forward, wearing headphones for ease of communicating with the other at the helm.
- Prepare the anchor and initial amount of chain ready for dropping.
- Circle around the area, checking how other boats are anchored and lying, watching the depth sounder. Watch the color of the bottom (if possible) and look for sandy spots. Avoid places where the bottom slopes downhill.
- Pick a spot just behind or off the quarter of another boat and calculate the scope needed according to water depth, state of tide, and weather.
- Go slowly towards the spot, headed into the wind, so that all way is off as we reach the spot.
- Slowly drop the anchor and lay it on the bottom, then as the boat drifts back gradually release an additional amount of chain 2-3 times the water depth. Avoid piling chain on top of the anchor. Let the boat drift back in the wind. (Callipygia always turned side to the wind at this point, which was sometimes disconcerting to other boats, but that's how she did it.)
- Patiently wait and watch her drift back and then slowly turn nose to the wind, telling us that the anchor is holding. Talk to her. If this doesn't happen, assume we're dragging and start hauling in the chain. If that brings her round, then the hook has bitten and we can continue anchoring. If not, then haul up anchor and begin again.
- Once the bow comes round into the wind let out more rode to reach the desired scope, and repeat the previous step. For all chain in calm conditions with adequate room we do about 4:1 scope (considering depth, plus tide, plus 4' for the boat's freeboard). We put out a bit more if it's shallow, a bit less if it's deep or very crowded. We increased the scope if it's very windy or rolly. Once we're beyond the chain and into chain and rope, we also increase the scope accordingly.
- Once the boat headed back with bow into the wind and the anchor rode going straight ahead, gently go into reverse, and gradually increase RPM's a bit for about 10-15 seconds. Watch the rode tighten, and then bounce when the engine goes back into neutral. If in doubt, feel the rode for vibrations (an indication that it is skipping along the bottom). If the bottom is mud, stay at very low RPM's. We don't do a big power set on initial anchoring. We'll do it later once the anchor is dug in or if the weather forecast warrants it. The Delta is a burying anchor and needs to sink in along with some of the chain.
- Note our position relative to other boats, and landmarks, and take a GPS reading.
- Once she seems to be secure, turn off the engine. If we have all chain out, put on the snubber to add stretch to the rode and take strain off the windlass. Put chafing gear on the snubber. If we have all chain out plus some line, tie a dockline with a rolling hitch to the rode, and secure it to a deck cleat to take the strain off the windlass. For the next hour, check our position periodically to make sure we're in the same place.
When at anchor we had some standard practices that we followed. Additionally, if the weather deteriorated, we sometimes initiated an anchor watch until conditions improved, as follows:
- Turn on the boat instruments (if available) and monitor wind direction, wind speed, boat speed, water depth, GPS position, and barometer. Log these every 30 minutes
- If you think you're dragging anchor, take emergency action
- Do an all around check every 20-30 minutes to make sure we're not dragging, or endangering/endangered by any of our boat neighbors, and look around for boats that may be dragging in our direction through the anchorage
- Prepare the dinghy so you can go help a dragging or unoccupied boat if needed
- Check for chafe on the anchor rode or dock lines periodically, and make sure nothing has come loose on deck
- Monitor VHF Channel 16
- If there's heavy rain, after the decks are cleaned open the water tanks to catch it
Our worst anchoring incident occurred in Scarborough harbor, Tobago, on December 2, 2003 (see the Ship's Log). We withdrew a bunch of points from the Black Box that night. What we learned was:
- Avoid very constrained or overcrowded anchorages if at all possible
- If we must use such an anchorage, then anchor on the outside edge of it, as far away from shore/piers etc., as possible.
- Always put the snubber on if you have an all chain anchor rode out
- As soon as we notice that the wind is really up, get into the cockpit and be ready...
Another time we were exhausted by the time we came into a very crowded and deep anchorage and didn't take enough time to circle around to find the best spot. Then, when it came time to leave, we needed a third hand to help haul and stow the anchor rode under power so as not to yank up another boat's anchor.
In anticipation of high winds in rolly Prickly Bay, Grendada, in June of 2003 we bouyed the anchor chain ahead of time, attaching our big orange float and a fender to the chain about 20' away from the boat. This added additional stretch to the chain catenary and buffered the boat's motion. It seemed to work well. While many boats in this rather deep anchorage dragged, we stayed put nicely.
We often saw other boats have trouble anchoring. They were usually charter boats with crew who hadn't had a lot of practice, or charter boats with inadequate ground tackle. But some cruisers just seemed to make the same mistakes over and over. The most common mistakes we spotted were:
- throwing tons of chain overboard right on top of the anchor
- doing a big power set before the anchor had a chance to dig into the sand or mud.
Storm anchoring is described in our hurricane preparation notes.
Bill Dillon (KG4QFM)
and
Pat Watt (KG4QFQ)
This page was last modified on
August 9, 2009
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