There are five factors that determine whether or not you have obtained a secure anchor. It is important that the boater does not overlook any of these five factors when anchoring his boat. Failure to comply with just one of them could have serious consequences for the navigator.
The first factor to take into account is the seabed. Is the seabed made up of rock, soft mud, hard clay, or some combination of all of these? Consulting your graph for the area will provide you with the answer that will allow you to choose the best anchor based on the type of bottom. Hard mud or clay provides the best gripping ground. If you can’t determine the type of seabed, you should use a larger plow or claw anchor.
The second factor to consider is protection against wind, sea and waves. The best anchorage will provide protection from the wind and sea from at least three sides. In areas where the wind is constant, choose an anchorage that protects from the most prevailing wind. If you are in an area where the winds are constantly changing, find an anchorage that will protect you after the wind changes. Finally, if large swells are encountered, plan to let more horse out to accommodate them.
The third factor to consider is tides and currents. You need to know the tidal range in the area you are anchoring in in order to correctly calculate range. This is easily accomplished by consulting a tide table for your location. If in an area of changing currents it is best to put two anchors.
The fourth factor to consider is swing clearance. Are there other boats in the anchorage using one or two anchors? In areas where 180 degree current changes are experienced, two anchors will keep the boats rolling at about one length. Remember that at an anchor, a boat will swing in a circle with a diameter twice the amount of sailing there is. And finally, stay away from any boat that you feel is not properly anchored.
Factor number five is drag indications and headings. To check for drag, do the following: With a tension on the anchor, stick your arm out and place the back of your hand on the rope. If you feel any vibration your anchor is dragging. When safely anchored, look at a prominent object on the shoreline. Record the heading in your log and check it frequently against the same heading that is safely anchored.
By looking at these five factors, you will be securely anchored. You will prevent your ship from drifting and possibly ending up against the rocks or crashing into another ship in the anchorage. And you can take comfort in the knowledge that you’ve taken all the steps that mark you out as a responsible and prudent sailor.