ANCHORING

A  Different  Approach

By

Andrew L. Peabody

  There are many different anchor types to choose from. Many boat owners are influenced by advertising or marketing by the major anchor manufacturers. Ads usually state that the anchor manufacturer’s anchor is considered best by some publication or because of tests conducted by the manufacturer. Their anchors can always be seen at boat shows and pretty ladies will attest to the fact that their anchor is indeed the best one can buy.

  Tests by manufacturers are normally done in sea bottoms that are most favorable for the manufacturer’s anchor and the results are always very conclusive that their anchor is indeed the best.

  However, more boat owners ask other boat owners whom they respect “What is the best anchor for my boat?” Then they will receive the answer that the anchor on the other boat owner’s bow is indeed the best anchor for them to purchase, since it had served him well in the past.

  Thus, the new boat owners will conclude that the tried and true CQR, Delta, Danforth or Bruce are the best anchors for their boats and they will happily go to their boat equipment catalog and order the new Chinese made copies of the above mentioned anchors at a very low cost. They will consider their savings a great bonus, and then be able to spend more on some electronic gadget that may last for a year or two before breaking down.

  The new boat owner will be told when purchasing one of the above that he must also buy a chain anchor rode (which attaches to the anchor and with the other end through a windlass down into the anchor locker under the foredeck). The salesman will tell the new boat owner that in order for the anchor to work properly, it must have a chain rode for it to set and hold. However, chain is very expensive. It is very heavy. It may kink up inside the chain locker when one wants to release the anchor causing much stress on the part of the boat owner. It is very muddy when it comes up from a mud bottom and it will spread mud all over the foredeck as well as leaving increasing amounts of mud deposited in the anchor locker. The savings that the boat owner thought he was getting on the anchor has been cancelled out by the great quantity of chain that he was required to buy.

  Then the salesman tells the buyer that “No anchor works in all bottoms.” The salesman recommends another anchor for other bottoms, then sells some more chain and the new boat owner is hit for some really big money. And because the chain weighs so much, the boat owner must have a anchor windlass that costs another $2,000 or so.

  The new boat owner then finds that after installing one of the above mentioned brands or their discount versions that he must restrict his anchoring to the type of bottom that is recommended by his old trusted boat owner friend. If he ventures out on his own without that advice, he may find that his newly purchased anchor does not perform as he had expected in the muddy bottom or coral bottom or grassy bottom or rocky bottom. Then he becomes quite distressed for he has made a huge investment in his anchoring system.

  Well what is going on here? The anchors described above along with many other brands or types new or fairly new on the market are designed to set with the anchor rode on the sea bottom. First, the anchor chain creates friction with the bottom which in turn causes the rode to hold the boat with some holding power all on its own. The anchor attached to the chain is not essential unless a storm appears. When that happens and the anchor is called upon to do something, it will act upon the bottom as it is pulled by the boat by penetrating into the bottom between one and two feet. Then, as the winds, tides and wave action increases on the boat, the anchor begins to do what it is designed to do, create a furrow on the bottom just like a plow would do in a field. This is what is called dragging. Dragging is very dangerous as it will cause the boat to drift onto the shore or out to sea. It normally happens at night (when most boats are at anchor) and all aboard are asleep. After the boat starts to bounce on a rock or the shoreline, the new boat owner will rouse his crew and attempt to get his boat back into safe water again. However, from that point on, he will never feel secure at anchor again, and his wife, the Admiral, will tell him to stay up at night to watch out for his new anchor dragging whenever he hears the winds blow.

  There is a more secure way to anchor by firstly going back to the original purchase procedure. If the new boat owner is knowledgeable about computers, he can consult the computer information dispensers such as Yahoo or Google and ask about boat anchors. He will then see a number of boat anchor websites that may inform him about the attributes of different anchors. He may also be influenced by a publication by the name of Practical Sailor or Powerboat Reports, both of whom offer free advice on products that they have tested and consider good or bad. Unfortunately, their tests on anchors leaves a lot to be desired since they have not tested anchors as a boat’s anchor would be tested in a storm.

  He may come across a website or two on a different type of anchor, a penetrating anchor. A penetrating anchor is designed to penetrate the sea bottom deeper and deeper into that bottom the more pressure that is put upon the anchor. As the anchor digs deeper, the anchor’s holding power increases. It works best with a cable rode. Most boats are not equipped with drum type reels as on a winch. So the next best rode for a penetrating anchor is a braided nylon anchor line. (Braided line will not kink
up in the anchor locker, whereas a twisted nylon line can kink up and cause distress to the boat owner.) Anchor chain will impede the penetration designed into the anchor. It is likened to a 2 ½ inch steel strap that is laying on the bottom, causing the anchor to stay close to the bottom’s surface.

  A braided nylon line provides much greater strength than an anchor chain unless one goes to outsize chain. The braided nylon line provides a good bit of stretch, which is a good thing. It does not bring up much mud when retrieved and it does not leave mud all over the foredeck or mud deposits in the anchor locker. It is the least after cable impediment to restricting the penetration of the anchor.

  There are only two types of penetrating anchors. The Super Max anchors have been available and in use since 1990. And now the new XYZ anchors have become available this year (2006).

  Let us start with the Super Max anchors. Originally called Max anchors, they were improved about six years ago by the use of a special tool steel imported from Sweden to make them at least 50 % stronger. After the new steel was incorporated into the manufacturing process, the anchors became known as Super Max anchors.

  There are two different types of Super Max anchors, one that is called adjustable and the other, the rigid. Both types work well in virtually all sea bottoms. There is no need for another anchor that will work in mud. The adjustable Super Max has an arm that is bolted to the shank with a fulcrum stainless steel bolt and a positioning bolt. The arm can be moved into three different positions. The lowest arm position is for sand, coral and hard mud bottoms. The middle arm position is for muddy bottoms and the upper arm position for ooze or soup.

  The rigid Super Max has its shank and fluke positioned half-way between where the lower and middle arm position would be on the adjustable anchor. It will work in all bottoms. In sand, coral and hard mud bottoms, the scope needs to be at 3 to 1. In mud bottoms the scope needs to be set at 5 to 1. If the bottom is unknown, the boat owner should try to set the anchor at a 3 to 1 scope, and if it does not set immediately, go to a 5 to 1 scope.

  These anchors need a braided nylon line for their rodes. As mentioned before, chain will impede the penetration. When anchoring with the adjustable anchor, one should use a 5 to 1 scope with the arm set in the appropriate position for the bottom type. Changing the arm position on the adjustable anchor is a simple process requiring a wrench. The positioning bolt’s nut and lock washer need to be removed, the bolt slipped out and placed in the new positioning hole, the lock washer and nut replaced. This process should take less that a minute to perform.

  What happens when these anchors hit the bottom? Let us assume first that the anchor sits on the bottom on its side with the fluke high above the shank. When the boat is backed down slowly, the anchor will set almost at once because the fluke’s leading edge which is sharp has all of the weight of the fluke and part of the shank on that leading edge. That causes the anchor to dig immediately into the bottom though grass without disturbing it or any other substance. The anchor rotates down into the bottom until it is upright and both leading edges of the fluke on either side are holding the same amount of substance, which then keeps the anchor solidly in an upright position as it penetrates into the bottom.

  If the anchor falls to the bottom in an upright position (not likely), then pulling on the anchor will cause the center tyne to imbed itself into the bottom and the anchor will then perform as mentioned above.

  The rigid anchor works the same way, but will not penetrate as quickly as the adjustable when the adjustable is set correctly for the bottom. Because of its lesser angle of attack to the bottom, it will normally require a few more feet to set properly.

  As pressure is applied backing down on these anchors, the anchors will penetrate deeper and deeper. Tests have shown that the anchors will creep slowly as more and more pressure is applied. This is normal as the anchors penetrate deeper.

  What happens normally at an anchorage when high winds occur overnight is that the Super Max anchor will be pulled by the boat when backing down to a depth of perhaps six feet. By morning the anchor could be down another ten feet or so, depending on the wind velocity. The softer the bottom, the deeper these anchors will penetrate. One individual found his anchor had penetrated 48 feet through soft mud down to the gravel bottom of the Cooper River at Charleston, SC. How did he know that? His anchor brought up the gravel as evidence.

  What happens when the wind is increasing as in a hurricane and is constantly veering. The Super Max anchors have a shorter shank and arm than the traditional anchors and so the anchor is more easily turned to the same direction as the wind against the boat. Because the fluke’s shape equalizes the load upon the anchor, it will not rotate out of the bottom as would a Danforth type.

  You would think that because these anchors penetrate so deeply, they would be impossible to retrieve. Not so. When the anchor rode is straight up and down during retrieval, it should be tied off to a cleat or around the windlass. The boat should then be backed down slowly at first, then with increasing rpms. The anchor should dump its load when at a 1 to 1 scope and as it is pulled up by the boat’s movement in reverse, come to the bottom surface at which point the boat will begin moving rapidly in reverse.

  If the anchor does not surface quickly, then it may be caught on an underwater obstruction. If a trip line is installed, the trip line should be cleated off with the boat directly over the anchor, and then the boat should be moved forward until the anchor is free.

  Trip lines are recommended for any anchor. A good way to install a trip line is to attach the line to the back of the anchor, then using 40 feet of trip line, attach the other end to the anchor rode 30 feet up on the rode. On a braided nylon rode, the trip line should be tied off using a ratline hitch (rolling hitch with an extra tuck). When the anchor rode goes into the anchor locker, so will the trip line. The trip line should be at least 3/8” or larger depending on the size of the anchor rode.

  Attaching a float to a trip line is also recommended as the float will indicate to others where your anchor is. By so doing, other boaters should stay well clear of your anchor.

  With Super Max anchors, one can clean the mud off of them effectively by leaving the anchor below the water’s surface for several minutes while the boat moves forward slowly. The anchor will track with the boat’s direction and clean itself up quickly.

  Another attribute of the adjustable Super Max is that one can anchor in really deep water by adjusting the arm up one position and using a scope of as little as 2 to 1.

  What makes the Super Max anchors penetrate so deeply? First it is the angle of attack of the fluke entering the bottom. Because different bottoms have different viscosities or gooeyness, the anchor’s angle of attack needs to be changed for those differing conditions. So if the arm position is correct, the angle of attack will be correct.

  The reason they hold so well is that there is much more fluke surface facing the bottom as the anchor penetrates that bottom. The greater the fluke area, the greater the holding. Traditional anchors have quite small fluke areas facing the bottom as they are pulled into it, so their holding is quite limited.

  Super Max anchors are heavier than the traditional anchors’ recommendations for anchor weights. The traditionalists recommend anchor sizes for boats between certain lengths. Thus a boat between 30 and 38 feet should have a Traditional 35 pound anchor. Super Max anchors are designed to hold boats in hurricane winds by themselves. For an anchor to do that job, it has to be heavier with considerably more fluke area facing the bottom. Super Max anchors are designed for the displacement of the boat, not the overall lengths. Why? Because the weight of the boat determines the momentum that that boat develops when it is at anchor. The momentum of a boat at anchor with chain rode can develop as much as twice the strain on the anchor system when the chain rode due to its catenary effect draws the boat forward and then snaps back when the winds pick up again. Thus a load of 5,000 pounds on the system can go to 10,000 pounds every time the chain jerks taut. The anchor is at the working end of this system and it needs to be of sufficient weight and efficiency to absorb the shocks and hold.

  Snubbers are recommended for all chain rodes. There are various methods of snubbing the chain rode. Some use a rubber snubber that will absorb some of the shock, but in really high winds, they are ineffective. The best choice is an all nylon braided rode which has lots of flex built into it. The next best choice if one has an all chain rode is to attach a braided line to the shackle holding the anchor, then bringing the line back to the boat and attaching it to a cleat or bollard. The chain is then used as a back-up and let out sufficiently so that it is not interfering with the nylon rode.

  The other penetrating anchor available now is the XYZ anchor. It is a novel new invention that uses fluid dynamics in its design to cause the anchor to penetrate deeper the more pressure that is applied. It is extremely light weight as a result, but it does get a large fluke area confronting the bottom while penetrating.

 It is designed to dig in no matter how it falls to the bottom. It has an extremely short shank (6 inches) to which is attached a cable or braided nylon line. Use it with a 5 to 1 scope regardless of the bottom. It will penetrate virtually all bottoms it has been exposed to to date. The anchor has not been around for too long, but it has set and held in some good tests by ABS (American Bureau of Shipping) and the inventor. Holding is dependent more on the anchor system, the rode, shackle and chain if used. In soft mud it will not hold as well as the Super Max anchors and its setting will be much slower. In sand it will set at once and provide exceptional holding as it penetrates deeper.

  The XYZ will shift direction as the wind shifts and because the shank is so short, there is very little strain put on to the anchor. Weighing only 13.5 pounds, it comes in either stainless steel or galvanized steel. A larger XYZ anchor weighing 27 pounds is available in galvanized steel. The bottoms that the XYZ works well in are sand, gravel, hard mud, mud and to a lesser degree soft mud. It is not recommended for ooze or soupy bottoms. It has not been tested sufficiently in coral or rocky bottoms to determine its characteristics there.

  These anchors are recommended strongly for catamarans and racing sailboats that need a good holding anchor with no weight. A windlass would normally not be necessary with these anchors because retrieval is so easy. Simply come directly over the anchor, tie off the nylon rode, then back down. The anchor will scoot to the bottom surface and you pull it up. A hole at the back of the fluke is where a trip line can be attached. Use a trip line as you would on the Super Max. If caught on an underwater obstruction, moving the boat forward instead of reverse during retrieval may free the anchor.

  Storm anchoring is a subject often discussed in magazines and by boat owners amongst themselves. The traditionalists will always tell you that one must anchor with two anchors cast out at either 45 degrees to the bow of the boat or 22.5 degrees to the bow of the boat so that there will be a 45 degree triangle set up between the anchors with the boat at the angle’s point.

  What happens during the storm is that the boat will swing from one side to the other with the wind, first overloading one anchor rode and then swinging to the other and overloading it. With the traditional anchors, each will drag when the boat is on its rode, then the other anchor will drag when the boat shifts to the other rode. Dragging during the storm is cut down by perhaps 25 per cent by using this method. However the boat will still drag and the anchors will soon be next to each other and perhaps fowling each other as the dragging continues. When the anchors have come together, they will offer the most holding power.

  So why not drop both anchors in the same line and just a few feet apart? This would offer the most holding with two anchors. However, with traditional anchors the penetration is so limited that the anchor further away from the boat can have its rode fowled on the anchor closer to the boat. Fowling will cause abrasion and abrasion will cause breakage eventually. A fowled anchor could be turned sideways and thus be totally ineffective. When dragging occurs, the fowled anchor will create a large furrow in the bottom which in turn will make the other anchor drag faster as it travels through the same furrow.

  For hurricane anchoring, some have recommended having three anchors out at 90 degrees from each other. The boat then is looking at anchors directly to port, directly in front and directly to starboard. In a hurricane the winds will veer around 360 degrees. Where you start with the winds to the east, the veer will be to the north, then to the west, to the south and maybe back to the east. With the anchoring system described above with three anchors using traditional anchors, the dragging will cause all three to ultimately come together and the turning winds will cause the rodes to twist around each other, making retrieval an all day job.

Another method recommended sometimes by traditionalists is to attach one traditional anchor with a six foot rode to the back of the first traditional anchor, then set both at the same place. This is a better solution than any of the above because the anchors cannot fowl each other and minimal chafing would occur. However, the first anchor when overloaded will start dragging and creating a furrow. The second anchor merely follows in that furrow and offers very little holding power, if any. Again with these traditional anchors, the boat will drag all over creation.

  Instead of the nightmares described above, a much more secure method of storm anchoring is to have at least one storm anchor a penetrating type, preferably a heavy Super Max that is designed for the weight of the boat. It is set with a 5 to 1 scope. Just beyond and in the same line with the Super Max, the second anchor is set with the traditional anchor’s recommended scope of 7 to 1. As the winds intensify, the Super Max rode will disappear into the bottom as the anchor penetrates deeper. The traditional anchor’s rode can travel over the Super Max rode without ever touching it. With the winds veering, the Super Max rode will hold the boat while the traditional rode goes slack all around the clock. Retrieving the anchors after the storm is over is not difficult as there will only be one twist in the two anchor rodes. Retrieve the Super Max first, then clear the traditional rode and bring it up.

  Several boat owners during hurricanes have used just one Super Max anchor with excellent results. Two cases reported steady winds of 146 knots and the boats didn’t move at all with but one Super Max anchor. Having two Super Max anchors is
recommended though, placing one in front of the other. When a hurricane comes, a tidal surge normally occurs if the hurricane comes in to the east of the boat’s position. If to the west, there will be an ebbing or extreme low tide. With two Super Max anchors, one set at a 5 to 1 scope at the high tidal surge depth and the other set at a 5 to 1 scope for the lower tidal depth, the lesser rode being closest to the boat, the boat should ride securely throughout the storm.