Anchoring Part 19: Rough Weather Techniques

Here are proven techniques for anchoring in rough weather I have used successfully, the special challenges rough weather anchoring brings and the pros and cons of the larger decisions.

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One Response to “Anchoring Part 19: Rough Weather Techniques”

  1. Jerr Says:

    Here are proven techniques for anchoring in rough weather, the special challenges rough weather anchoring brings and the pros and cons of the larger decisions.

    In storm conditions, double your anchors and use all the chain you have, as well as kellets. In near gale conditions, the normal size of everything for your boat will need to be at least a full step up and doubled. In full gale conditions, double that again and increase everything in size again: The force increases as many times the square of the windspeed because wave force also increases exponentially and spray drastically increases the force of the wind. This is why it’s so much of an advantage to duck behind an island during a gale – Lowering the wind from sixty knots to forty knots doesn’t just take the sting out of it but reduces the forces by over half! The same is true for wave size, so finding a really good shelter can easily reduce the forces you face to a quarter of what they are on the open sea. If you have time to set moorings, when truly violent weather sets in, by all means do so in conjunction with traditional anchoring techniques – Especially if wind shifts are expected.

    With the large advantage of a protected lee comes a grave danger: Grounding. Being thrown ashore or on a reef in a storm is certain to lead to loss of your boat, injury and probably death. At sea, a well-built, prepared bluewater boat will be awfully uncomfortable in a bad storm but will survive with little or no damage and almost certainly no injuries. If there is a choice to be made in a dangerous anchorage, head out to sea. Never, never get trapped on a lee shore!

    Powerboats have a much worse danger: Running out of fuel or having crud in the fuel tanks knocked loose, clogging all the spare filters and in either case, not being able to power back to port. That is why common powerboats are not safe in storms, even if they are stable and stiff. Onboard fuel polishing, multiple filtering systems and regular tank maintenance, in addition to plenty of spares of all kinds are critical for bluewater powerboats. By the way, these are excellent for sailboats, too – Nothing’s as frustrating as fuel problems at sea and those problems always show themselves when conditions deteriorate and maintenance is most problematic.

    While being forced to anchor in a lee, to wait out a gale is understandable, being forced to anchor in a hurricane is a failure of judgment from the start: No one should be in hurricane zones during hurricane seasons. With global warming, we should expect more and stronger hurricanes, in addition to longer hurricane seasons. Very few boats are designed to withstand hurricanes and there are many factors that are completely out of anyone’s control or ability to predict: Trees flying through the air can kill everyone onboard and sink your boat. Floating debris, flung by waves, can easily hole and sink any fiberglass boats. Other boats dragging through the best mooring can destroy it before anyone knows what’s happened. Multihulls simply turn into kites and fly to their doom. Surge and breaking waves can be astounding in every way imaginable. Be smart and plan your travels with profound respect for Mother Nature. You’ll find plenty to explore, almost everywhere you go.

    Unusual conditions and problems in heavy weather
    (1) Rip Currents: One condition that can be surprising in strength in heavy weather is currents. Rip currents, in particular, can be amazingly strong and often carry large debris, such as tree trunks. Fortunately, rip currents are fairly predictable, once they’re in action and moving perpendicularly to their flow will get you out of them. They tend to form in the same place and are the result of a large amount of water piled on the beach by strong, frequent waves. Eventually the mass of water on the beach, above the waterline, becomes so great that it forces a way out and that’s the rip current. Because the wave action is towards the shore on the surface, the rip current is fastest, deeper. As the current clears the wave zone, it dissipates but can still be deceptively strong. Never swim when rip currents are active. If at all possible, avoid taking dinghies across them, as debris caught in the rips can surface unexpectedly, damaging props and puncturing tubes.

    (2) Wave Bounce and “Potato Patch:” When two or more wave trains intersect, they are additive at sea level. In practical terms, this means a tall wave meeting a deep trough will cancel each other at that point only. When the tall wave then meets the tall wave behind the deep trough, it’s like two sumo wrestlers bashing together, with an extra-tall spike where they hit. A shallows that encourages such an intersection is called a potato patch and these are treacherous and exceedingly dangerous because these wave intersections have double the force and double the suddenness in impact. A potato patch will look calm in calm winds and is only evident as the wave trains collide, in rougher weather. You can often find them by:
    • A lack of thick kelp with a sizable offshore plateau, off a straight shoreline
    • Measuring the angle waves hit the shore, taking the complimentary angle, finding the strongest intersection and seeing if it’s especially shallow
    • Empirical testing: “Yep – It’s lumpy here, too!”

    (3) Wild Wind Gusts and Sudden, Major Wind Shifts Hopefully you have chosen anchoring equipment for the maximum conditions you are prepared to endure and not for price, weight, stowage space or other convenience. A strong gust can part your anchor line and chafe can do the same if it’s too thin; if your anchor is too small, drag it out; If your chain is too short or light, swells raising your bow will pop your anchor out. If your boat is sailing at anchor, a gust can lay you over, greatly increase your speed or whip the boat around as it tacks. A sudden, major wind shift can dislodge your anchor and cause a reset or drag.

    One thing to keep in mind is to always anchor with an escape plan, be ever vigilant and never get trapped on a lee shore! I can’t stress this enough. A boat is generally safe at sea but never in rough weather around rocks. The captain of a vessel is responsible for all aboard and an anchor watch is part of that responsibility. Sometimes, an anchor watch may just be listening to a daily radio report or checking in by cell-phone with a reliable watch-person but it needs to be there. An idyllic, snug cove can easily be a death-trap in rough weather. A perfect example of this was at one of my favorite anchorages, Coches Prietos on Santa Cruz Island, in the Northern Channel Islands in Southern California. I woke from a nap on a lazy day to an especially clear sky and flat sea, a bit more than the day before. There was a slight heaviness in the especially still air, so in case a Santa Ana wind was brewing, I woke my friend and we frantically started putting things away to leave. We managed to leave inside of five minutes, pulling up both fore and aft anchors and by that time, the wind was blasting down the canyon at over 45 knots – To say we were awed would be an understatement. The winds topped 60 knots and blew three days, unrelentingly. There was a lively bunch at the marina, sharing stories! By the way, I let the stern anchor out first, taking in the bow anchor. This gave me the freedom of hanging on the stern anchor if there was a problem with the bow anchor and the opportunity of easily casting or even cutting the stern anchor line. A great way to cast off an anchor line is to tie a fender or bleach bottle to it: You can always retrieve it. You can not retrieve a boat that has been smashed on the rocks.

    Unusual conditions, problems onboard and safety, anchored in heavy weather While this is a subject a book could be written about, I’ll limit this discussion to a brief overview of moving about on deck. Some of the many other things to keep in mind, depending on your temperment are duplicating engine filtering, securing loose objects, sleeping with leecloths, sophisticated and easy one-pot comfort meals, entertainment and selecting a boat made for heavy weather.

    How to use jacklines, tethers and lifeline nettings well Few sailors use jacklines and tethers well but you can if you think about their purpose – Keeping you onboard or at least chest-high at the toerail if you do fall over the lifelines. That is only possible if:
    • You wear and secure a properly-fitted, appropriate harness, which can be built into jackets.
    • The jackline is far enough from the toerail.
    • The tether is short enough to keep you from falling into the sea.
    • The lifelines have strong nettings.

    This last point is very important, as the distance from the boat’s jacklines to the toerail is the same as from the jacklines to the upper lifeline but going over the top gives you an extra 2-1/2 feet of length for your tether. In other words, holding you 2-1/2 feet higher when you fall overboard. From the water, grabbing the toerail, it’s amazingly hard to climb the freeboard to get to that last bit, over the rail: Only fairly athletic people can generally do that. It is possible for most people to get from outside the toerail onboard alone, though. Tethers that are too long, jacklines that are near the sides and lack of strong lifeline nettings are literally the difference between life and being dragged to a drowning death for the person overboard.

    I like to leave one deck clear to the bow for quick access, even though this gives more windage on one side than the other and I’ve not got a choice of staying on the high side. I run my jacklines as close to the center of the boat as I can reach, to prevent me from falling overboard. Sure, it’s easy to run jacklines on the deck but if you fall over, they will only hold you half in the water, pinned to the side of the boat. Have you ever tried boarding your boat on the side, from the water, with soaked clothes? It’s nearly impossible. Properly run and used jacklines will keep you out of the water, at worst, dangling from the lifelines with your chest at deck level. Here is how to manage jacklines, tethers and padeyes:
    (1) Mount padeyes at every entrance: By the companionway, at the forward end of each cockpit coaming and just forward the dodger, either side and inboard, if your cabin rail does not extend within reach from the cockpit with your tether stretched.
    (2) Run jacklines as close to the center of the boat as can be reached.
    (3) Keep your tethers short – One four feet and one six feet.
    (4) Keep tethers ready and clear of entanglement, clipped to your chest harness when not in use.
    (5) Always clip the new tether in before unclipping the old one, to get around objects.

    If this happens, here is how to get back on board with the minimum of effort. The trick is in leveraging your body up in increments, holding onto those increments creatively and then using a different set of muscles to get just a bit farther onboard. It’s much more effective than trying to pull straight up and I commonly used this method when I was climbing rocks professionally, in my twenties, to mount overhangs, which are a good bit harder than the side of a boat!

    How to board if you’re tethered and blown over, with the minimum of effort.
    The trick is in leveraging your body up in increments, holding onto those increments creatively and then using a different set of muscles to get just a bit farther onboard. It’s much more effective than trying to pull straight up and I commonly used this method when I was climbing rocks professionally, in my twenties, to mount overhangs, which are a good bit harder than the side of a boat!

    How To Board the Side of a Boat With Lifeline Nettings
    (1) Hook a heel on the toerail.
    (2) Grab the upper lifeline with one hand and the toerail with the other.
    (3) Using your heel as a fulcrum, take your weight up with your lower hand on the toerail and pull down with your upper arm, pulling up.
    (4) When you can rotate your elbow above your lower hand (upper shoulder near the upper lifeline), you can then push up with your lower arm and hook your armpit over the upper lifeline. This is a relatively secure spot but get on board as fast as possible – You can easily be knocked into the sea again!
    (5) put your lower leg’s knee on the toerail and pull yourself up, just over the lifeline and tumble onto deck.

    How To Board the Side of a Boat Without Lifeline Nettings
    (1) If possible, grab a stanchion and pull up, to grab as high as possible.
    (2) Hook a heel on the toerail: If it’s to the right, use your right heel and if it’s to the left, use your left heel.
    (3) Grab the upper lifeline with one hand and the toerail with the other.
    (4) Using your heel as a fulcrum, take your weight up with hands and pull up strongly.
    (5) When your hips are near the deck level, sneak your other leg between and onto the deck. You should be able to easily get your lower leg onto the deck.
    (6) Slide your hips and outer leg onto the deck, still pulling up strongly with your hands, until you’re sitting on the toerail. This is a relatively secure spot but get on board as fast as possible – You can easily be knocked into the sea again!
    (7) Now the scary part: Release the upper lifeline, grab the lower lifeline and pull yourself onto deck – You will have to let your upper body sway away from the boat for this and that’s why it’s scary. The momentum you build in lowering your upper body will slide you onboard with your hands as fulcrums.

    Importance of navigation at anchor in heavy weather Take bearings, set depth and GPS alarms and understand the nature of your anchorage, as well as the stretch and behavior of your rode and the resetting properties of your anchor(s). That way, you’ll not only know where you are but why your boat is behaving the way it is. While waiting out a blow, hiding behind a spit of land in Baja, Mexico, our rode stretched 30%. It didn’t start to yield but we kept an anchor watch and once the rope “set” and I saw our chafe protection was working well, I was happy with our anchoring and slept well during the three days of 20-45 knots of wind. We kept an anchor watch throughout the storm, anyway. It’s especially important to do so because hings happen so much faster in high wind and they’re almost always bad: Loose crud is knocked loose in the fuel tank by wave action and that fouls the filters, killing the engine, etc. If you need to, use an alarm but regularly do everything you ought to, at watch and supervise those you’re not absolutely sure of: It’s your life theyr’e not looking after and things really do go wrong. If you’re on top of your game, you can take preventative action before a problem becomes a catastrophe.

    Anchor deployment In heavy weather, the holding ability of anchor, chain and line become important. If you follow my recommendations, your chain and line should be fine and your anchor will pull through sand or mud before any other failures. That’s a good way for the system to fail, because it can be reused without further problems. In a near gale, two anchors in a 45° V are best, if the wind direction is steady. This gives enough separation for one anchor to fight sailing at the other anchor and splits the force generally in half, doubling your holding power and additionally, acting as backup in case of a line parting on an unseen wreck (How did that get there?). Be very, very wary of ever using a stern anchor in rough weather – It will hold you to side to wind and sea if anything shifts and that can quickly become catastrophic. If there are wind shifts, feel free to lay out a pattern of anchors so you have several in each likely direction. If you have a keel-stepped mast, tying your rode around the mast is best, especially if you’re out of room on your bow cleats. It’s also a very good idea to keep one anchor line per cleat, so you can haul any in or let any out, as needed. If you don’t have enough chain, get creative and use anything that’s really heavy and sturdy (I cover that below, in this article.).

    Protecting against chafe A separate, appropriate and intelligently-mounted anchor roller for each anchor rode is the best chafe protection available: The roller not only is round and of a large enough diameter to not bind rope as it goes over the edge but it rolls as the rope stretches. If the line is only going straight, there is no need for further chafe protection. If, however, the boat is sailing at anchor, the line will pull from the side of the roller cage, from the bail, side or worse, the junction of the two – Pinched and being cut as the rope stretches. To prevent this, there are two options:
    • A gently-rounded anchor roller sides and a top that curves inward, forcing the line down.
    • Leading the line through a gently rounded hawse, which is best in heavy weather because there is no way to pinch the line. If this is the case, there must be a short distance between the hawse and the cleat, to keep the line from wanting to saw back and forth as it stretches. For the heat generated as the remaining stretch rubs the line against the hawse-hole, a pad of a thickness of layered cloth with a heavy plastic cover works well. A quick way of applying this is with a folded dish towel, duct-taped in place and a slit hose zip-tied (with the zip-ties well clear of the hawse) to the anchor line.

    If you have to deal with a poorly-installed anchor roller, holding the line down firmly on the roller will probably keep it from jumping up and catching or rubbing on the upper edges of the roller. This can be done with a line tied under the roller and around the anchor line with a rolling hitch, keeping pressure on it. A taut-line hitch is a great way to adjust tension, here. In all this, remember that line thins as it stretches, so tying chafe protection on the line is problematic: If it’s tied before stretching, it will be loose and the rope will rub inside, generating heat and thus weakening the line. The only ways to avoid this are to have enough of a length of the protecting cover so that the cover stays with the line and moves with against the boat, have an elastic cover inside the outer chafe protection or use layers of protection. Layers of terry cloth between durable cloth work well.

    Maximizing effectiveness of your scope My favorite technique for maximizing scope is to drop the hook in shallow water, backing over deep water to anchor. It’s actually good for a Bimini Twist because the deep water anchor has to pull uphill and so wants to dig in especially well. The problem, of course, is that swinging is a problem and can be ruinous.

    Using a kellet to stabilize your rode Another technique that works well for maximizing scope is to weight the rode. This is called a kellet and is quite effective, particularly when there is not another anchor or rode. Only use a kellet as a last resort – While it does work well, anchoring well or putting another anchor out will work considerably better. The purpose of weighting the rode is to create a smaller angle to the seafloor from the chain to the weight, thus keeping the chain quieter and minimizing chances of pulling the anchor out due to large swell lift on the bow. The problems are that the anchor line now swings near the seafloor, catching much it did not, before, greatly increasing chances of fouling the rode and cutting it on debris, a wreck, corals, boulders, etc. For this reason, don’t weight the anchor line if there is a chance of much swinging over rough or unknown bottom. A canvas bucket, sewn closed or a reinforced plastic or metal bucket with a lid firmly strapped down can also work but there will probably be a lot of chafe and dragging, so a very strong arrangement in every way is most desirable.

    The farther away from the boat you can get the weight, the more efficiently it will work. This technique will work as long as the weight is close to the bottom, at least twice the depth, in length. The easiest way I have for weighting the rode is to:
    (1) String a scuba diving weight belt with all the weights I have.
    (2) Close the buckle around the rode in front of the boat (I have the flip type buckle.).
    (3) Tie the retrieval line with a figure-eight knot and a secure follow-through knot.
    (4) Duct-tape the buckle closed.
    (5) Sew the end to the belt with a lock-stitch whip. That whip is fast and easily cut with a knife, later and acts as a great backup, in case the buckle opens or breaks.
    (6) Ease the weight out until the desired length and cleat that line on a separate cleat from the anchor lines.

    Minimizing windage Besides the obvious – The wind-driven waves and swells, as well as the strength of the wind itself, act on the boat. Wind velocity increases with height, so in heavy weather, you will do best to take down things that block the wind high on your boat – Like your dodger, bimini and canvas enclosure. If you have any worries of your anchor holding, at least roll up or remove your eisenglass (clear plastic) bimini windows, letting the wind and rain blow through, rather than push your boat. If you can clear everything to deck level, you will lessen the force on your boat at anchor considerably, perhaps a third of the force off your anchor(s). Lashing items on deck fore and aft, in alignment with the wind also helps.

    Lowering a dinghy does decrease windage but also gives a mostly uncontrollable tail to your boat that will probably fill with water, yank itself to death, try its best to float away and be a general pain to deal with. If you can roll it up and stow it in a lazarette, that’s best. If it’s a RIB (Rigid Inflatable Boat), deflating it won’t give you much windage advantage and they’re so useful in anchoring, so keep it ready to go but lashed securely. I have laid second anchors, gone to help other boats and done many things in a dinghy while anchored, waiting out a blow: Dinghies are mighty useful.

    Avoiding swells Choose your anchoring site to take advantage of protection from swells in sharp points of land. Another, sometimes not quite so obvious thing to look for is something that breaks the power of swells – A thick kelp forest or a submerged reef can do wonders for breaking the force of incoming swells and waves. Reefs, submerged or not, can be godsends for reducing scope in tight quarters.

    Sailing at anchor The first thing to do is to lock your wheel or tiller. If you don’t have a steering lock, tie your tiller or wheel in place from both sides, taut, so it can not move at all. Any working of the rudder will encourage sailing at anchor. Start steering straight ahead but if you easily sail at anchor, try turning progressively more. This will only prevent sailing at anchor in a light breeze but will help in stronger winds. To truly take care of this problem, set an anchoring sail. It’s by far the simplest and most effective solution and will reduce the sailing to very little. Setting the anchoring sail initially dead ahead and gradually working the luff outboard with your traveler until the action is effective is best.

    Warping your boat If you don’t have an anchoring sail, you can at least keep the boat sailing only on one tack with a second line tied to the anchor line and stern. The action of pulling your boat out of true with this second line is called warping and the line tied from your anchor line to your stern is your warp. This will keep your boat on the midpoint of your tack, back and forth but only moving 1/3 as much as you would otherwise and with none of the tacking at anchor that is so unsettling. To attach this control line,
    (1) Tie an old halyard or a line that is twice the length of the boat, to the rode, a boat length ahead, with a rolling hitch (My favorite in this case is a prussic knot.).
    (2) Lead the line outside the boat to the spinnaker block at the stern or attach a block on the quarter if you don’t have one and lead it through that.
    (3) Bring the line forward to a winch and crank the boat slowly out of line with the rode. When the boat is about 20° out of line, it will start sailing. Keep the angle as minimal as possible to keep the boat from tacking – You will need a definite minimum angle of about 20° to achieve this. If the boat tacks anyway, just relax and let the boat complete that tack and get on the favored tack before hardening the line.
    (4) If your boat has a tumblehome or curvy stern, you will probably need to tie a couple of lines from your toerail to this control line with loose bowlines, to keep it from slipping under the boat. Tie these lines just long enough not to take any pressure when the boat is sailing at anchor, just before and after the keel.

    Minimizing pitch, roll and yaw and maximizing stability We have seen how to minimize large yaw (sailing at anchor) but not so much yaw from waves or swells. This, with pitch and roll are almost entirely from waves and swells and are periodic. As such, “Flopper Stoppers,” “Rock N Roll Stabilizers” and other harmonic motion dampeners work great… With a twist: In heavy weather, your boat must be assumed to be moving through the water, as the gusts increase and the rode stretches, as one rode pulls more for a wind set or as she sails at anchor. The dampeners must be clear of all rodes at all times. They also must be set to take unexpected lateral forces and be quickly retrievable in case of a need to exit fast, so hanging a dampener on a whisker pole is a bad idea, anchored in a storm. Similarly, hanging a dinghy on the end of an extended boom greatly increases windage and the chance of something breaking free. Because the motion is so strong, small dampeners will not work as well and large dampeners will pull like crazy on the boat, necessitating strong lines, chafe protection and strong attachment points. generally, dampeners should be hung aft, to remain clear of anchor rodes, in heavy weather.

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