Further info from the same thread;   

Originally Posted by smokeonthewater    also, most people don't put out nearly enough rope.... strong current + 30' deep = 150' of rope   
With a strong current, I'd go to as much as 7x, or 210' of rode. My rule of thumb is; calm - 3-5x; strong current or wind - 5-7x; strong current and wind 7 - 10x. Wave height will also play into this as well.

Bobby,
             Great info. The commonly accepted "ideal" scope of anchor rode to depth is 7:1. I have 200 feet of 3/8 three strand and 12 feet of chain for my small tinny which I use on fair weather days on Simcoe. On my Bruckmann 28' I use 200 feet of New England 7/16 three strand nylon, 15 feet of chain and a Fortress 16 anchor.
              Just a quick comment on the 7:1 scope. This is the standard for anchoring under extreme wind conditions. Often we are over 80 fow when fishing whities on Simcoe. Obviously impractical to carry and use over 500 feet of rode. Also, in the great majority of our anchorages on well travelled cruising routes such as the North Channel on Georgian Bay, experienced boaters set their anchors by backing down under power with the bow into the prevailing wind. They then shorten the rode to approximately 3:1 due to the number of boats that use these locations. A 7:1 ratio could look like a drunken knitting bee if a serious wind shift occurred overnight. The compromise is that 3:1 with a set anchor is fine but the anchor will not necessarily reset itself well on a short rode if the wind shifts and starts blowing heavily. Set your GPS alarm to waken you if your anchor slips and your boat moves beyond the set parameters. Sand is the best bottom in which to set the hook. I have experienced some wild weather on Georgian Bay where the only visible portion of my anchor and rode is a foot or two of chain and the nylon rope come morning. The actual anchor and almost all of the chain is buried out of sight in the sand due to the stress created by heavy winds on a wide beamed powerboat. For those mooring out, I'd strongly suggest you carefully check the strength of the cleats to which you may have snubbed your anchor rode. It is all too common for out of sight corners being cut by manufacturers, in this case poorly backed cleats and bow eyes, which will tear right out of the fibreglass or aluminum decking when subjected to undue stress such as that created by violent summer storms. As you pointed out, the inherent elasticity in nylon three strand, helps cushion these stresses to quite an extent. Use of a bridle (made up of a dock line) fastened to bow cleats on each side of the boat helps to distribute stress away from a single fastener. This isn't nearly as complex a process as it sounds. Actually, fresh water boaters have it very easy in comparison to salt water cruisers where you have to calculate tide fluctuations to ensure you have sufficient rode and water under you come morning, not to mention tidal currents and directional changes.
             Apologies for wandering from the original question.

excellent topic guys!!