There are many factors to consider before you choose and deploy your ground tackle. Some of those considerations are outlined in this article. I have outlined this into phases so simplicity.
Phase 1- General Anchoring Terms To Know:
Ground Tackle: The general term applied to anchoring a boat (vessel)
Rode: Anchor line and Chain
Scope: Length of the anchor rode measured in units of water depth (8: 1 ratio respectably) recommended
Shackle: A "U" shaped connector with a pin or bolt across the open end
Bitter End: The last part of the line
Have you noticed how many different styles of anchors there are? This can be especially confusing for the new boater. Some of the styles available are: Fluke, Grapnel, Mushroom, Plow and Navy. Newer anchors may be known by the name of the manufacturers such as Danforth or Fortress.
There are so many variables and requirements for adequate ground tackle, it's impossible to really establish a firm set of rules. Factors to consider are the type and weight of the vessel, characteristics of the ocean bottom found locally, the average depth of water in the anchorage area and the strength of the normal prevailing winds and currents. Without ground tackle can be depended upon to hold securely even while the boat is unattended, it is not adequate. The bottom line is that there are many variables.
Anchoring Know-How Phase 2:
With knowledge of the general terms and anchor styles, we have decided on the anchor needed for our particular circumstance. Next is figuring out what the diameter and length our line should be before we attach it to the chain and anchor. Most of us will utilize 3/8 "or" "line. We'll use 3/8 "line for boats up to about 4,000 pounds and half-inch line for boats up to about 7,000 pounds.
Larger diameter line will be needed for heavier boats. We'll need a length of line that will allow us to have a scope of at least 8: 1 ratio in the depth of water we usually anchor. Most of us will have a minimum of 100 '- 200' of line for our main bow anchor. I recommend having a second, smaller anchor onboard too. Use it as a stern anchor or lunch hook.
Deploying two anchors will allow you to anchor at the beach in close proximity of other boats without your boat swinging into your neighbors' boat. Having the second anchor allows you to deploy a smaller more manageable anchor while stopping for a quick bite to eat. This anchor should also have the same diameter line and chain as the main anchor with at least 100 feet of line.
Next, we determine the diameter and length of chain for the anchor. The size and weight of your craft will be factors in this calculation of the chain between the anchor and the line. Why do we need chain? The chain acts as a dead weight which assists in setting the anchor or digging into the bottom. There are different grades of chain, just to confuse us I think. Being budget minded, I use the Hot Dipped Galvanized type as most of my boating is in salt water.
We need adequate strength in our chain; Inch inch chain has an approximate breaking strength of 5,000 lbs. while 5/16 inch chain has a breaking strength of about 7,600 lbs. You guessed it, the thicker the chain, the stronger it is. I use six feet of 5/16 'chain with my anchors on my 4,300 lb boat.
Now we need to either splice or have spliced an eye with a Thimble in one end of our line. Through the Thimble we need to attach the chain by installing a Shackle and then on the other end of the chain we use another Shackle to attach the anchor.
Do not forget to insert a length of stainless steel wire through the head of the Shackle pin and around the shaft twisting its ends together. This prevails the Shackle pin from backing out over time. It is now time to do a back splice on the other end of the line to prevent it from unraveling / fraying. Of course, you can check out the pre-spliced Anchor / Chain Rode packages at your local marine store to save yourself time and work.
Anchoring Know-How Phase 3:
I recall a nice summer afternoon at a local beach. My friend and I were about 17 and just pulling up to the beach in my 16 foot Starcraft Aluminum boat. Bert was at the bow ready to deploy the anchor and I was at the helm. I looked to the stern to check the engine for a split second and when I looked forward, I observed Bert sitting in about two feet of water with the anchor in one hand looking baffled.
We had anchored that boat successfully many times in the past. This time however, he forgot the number one rule, keep feet clear of the line. He had become entangled in the line and as he thread the anchor overboard, Bert went out with it! This was good for a laugh as he was not hurt. It is best to lower the anchor, not throw it.
Another experience was on the other side of the same beach. With a raft of six boats spending the weekend, I asked the size of the anchor my friend had deployed. Six boats rafted together is a lot of tonnage and in an area which normally has a nine foot tide and a 4-6 knot current. I had recommended deploying a stern anchor in conjunction with the bow anchor. This I knew would prevent the rafting boats from swinging during the tide change.
My suggestion was rebuffed as over-kill and I was advised that this is the way they did things for years without a problem. Early the next morning we all awoke to a terrific thud. We were nearly thrown out of our bunks. You guessed it; the anchor lived during the tide change and as the boat swung it lifted the anchor which did not reset itself.
We drifted until the out-drive on my boat used the stern anchor-line of another raft of boats which swung us into that raft. This did stop us from going a bit further though, which would have been smack into a raft of Bertrams! Our insurance companies would not have been pleased. I do not know how, but there were no injuries or damage, just one more lesson learned.
Bonus Tip: Deploy two anchors when over-nighting in tidal waters.
Summary of Key Points:
o Practice your anchoring skills in areas of less congestion when possible
o Keep your lines neat and coiled
o Lower the anchor carefully, do not throw it
o KEEP feet away from the anchor line
o Tie off the bitter end to prevent anchor & rode from going overboard
o Replace worn rode