Originally Posted by solent
Reading theses posts explain why at some achorages yachts are swinging into the position of other yachts. There is a certain amount of rode required depending on the depth of water. The anchor is not what holds the boat, it is the water pressure pressing down on the surface of the rope as the boat pulls on it.
I hope I never anchor near you! The anchor IS most certainly what holds the boat. A good length of rode keeps the line more horizontal so the anchor can remain set and not yank out from a rode that is almost vertical. That is the most ridiculous logic I have ever heard and I've been sailing for 35 years. There is no downward pressure on nylon rope that is enough to even make a difference. Whn you get in the water is there downward pressure on you? No! Rope is the same it is actually ligher when it is in the water due to trapped air in the strands and the nearly neutral bouyancy of nylon. Now if you run an all chain rode than the weight of the chain is what keeps the line closer to the bottom not "water pressure"?? If the anchor does not hold the boat why don't you just toss some rode over board next time you're out and see where you wind up.
The proper scope for anchoring is 7:1 but in many anchorages you need to pull back to 5:1 or perhaps 4:1 but lets hope the wind does not blow. You should always set and BURY the anchor on a long scope like 7:1 minimum. On a short scope the anchor will only bury partially and not very deep. I anchor out constantly and frequently dive on my anchors . I have been dragged onto many times by inept idiots who don't know how to properly set an anchor so I make it sort of my mission to never drag and always set my anchor by backing down hard with a minimum 7:1 scope. I once handled a storm with gusts to 74mph. When we woke up in the morning the only other boat left in the anchorage, that was not on the rocks, was using the same scope as me a 10:1.
Keep in mind that scope is water depth PLUS bow height from water. Most sailors look at their uncalibrated depth sounder that is 12-18 inches below the surface and think ok I have 10 feet of depth I'll run a 5:1 at 50 feet. The reality is that in order to run a 5:1 in this situation you would need to add back the 1 foot for the transducer and the 4 feet of bow height making it 15 feet not ten! a 5:1 in this situation is 75 feet of rode not 50. So now most sailors are really setting 3:1 scopes and not burrying the anchor at all.
As for the ASA instructor barely passing the OP that guy should have his teaching certificate revoked he's an idiot..
Anchoring is easy:
Figure scope - water depth plus height of bow
Drop hook to bottom while already moving backwards (don't drop moving forward or you run the risk of fouling the flukes or shank when you set in reverse)
Pay out scope to 7:1+
Cleat off anchor rode and back down at about 2/3 throttle to make sure anchor is set.
Pull back to 5:1 if necessary
If wind picks up to 15-17+ go back to 7:1 if wind goes over thirty go higher with the scope..