Anchor Rode Scope Sheet

[Steve Bedford]

Recently, I had a couple customer questions. The first was about anchor rode scope. He is new to boating and anchoring. After a long discussion, I created a sheet (attached). He found it useful and suggested I share it.

Steve

 

[Frosty]

I like that you noted it's important to count the depth from where the anchor attaches to the boat. That can really add up and is not obvious to everyone.

If I were to add to it (not saying I would, heck, I didn't even make one and you did!), I might put something at the bottom about how to take high or low tide into account. Granted there is not a huge tide where you are. That factor was new to me when I first cruised in tidal areas (of course I chose BC with huge tides for my first go at them ).

 

[Steve Bedford]

Frosty,
That is an excellent comment: “take high or low tide into account.” I will indeed add this on any future distributions. Thank you.
Steve

 

[RickyD]

25 feet is as deep as you go? Dang, I'm used to 90 - 120'. I try to put down 3:1 but I think even that is overkill for our typical conditions and an all chain rode. With 300ft of chain out, who cares about the 5 feet off the water? The goal is to keep the anchor shank as close to parallel with the bottom as possible, which is accomplished with scope. If there is a blow, I can go 5:1 with 500 ft out. That is a ton of chain. I also could change to my storm anchor which is a Fortress 55. I don't normally use it because it wants a 5:1 scope and I would prefer to uses less. I use a Mantus M1 mostly with no issues in 3 years.

 

[boomerang]

That's a nice cheat-sheet ,Steve. Thanks. I think I'll print it out to keep onboard. I hate math so it'll help! I do remember to take the height of the bow into account but always forget my transducer is 1 1/2' below the surface with no offset incorporated into the reading...not a huge deal but it still could make a difference , I guess.

 

[Steve Bedford]

25 feet is as deep as you go? Dang, I'm used to 90 - 120'. I try to put down 3:1 but I think even that is overkill for our typical conditions and an all chain rode. With 300ft of chain out, who cares about the 5 feet off the water? The goal is to keep the anchor shank as close to parallel with the bottom as possible, which is accomplished with scope. If there is a blow, I can go 5:1 with 500 ft out. That is a ton of chain. I also could change to my storm anchor which is a Fortress 55. I don't normally use it because it wants a 5:1 scope and I would prefer to uses less. I use a Mantus M1 mostly with no issues in 3 years.

Good point. My customer shared where he intends to cruise and I did this for his intended anchorages. Obviously, there are others who need far more rode than I listed. At those depths, the 5 feet of roller to waterline becomes less significant. It makes a big difference in 25 feet or less of water.

Thanks for your response.

 

[Steve Bedford]

That's a nice cheat-sheet ,Steve. Thanks. I think I'll print it out to keep onboard. I hate math so it'll help! I do remember to take the height of the bow into account but always forget my transducer is 1 1/2' below the surface with no offset incorporated into the reading...not a huge deal but it still could make a difference , I guess.

Thanks Shawn. The customer I worked with on this did not want to have to add the distance from roller to water level to the seabed. He asked if I could adjust the formula to include his roller to water level. I said sure but asked why? He said his wife is at the helm and she reads out the depth as noted on the depth finder. He wanted her to read out the length of rode based on that depth finder reading with the roller to water level INCLUDED in the formula. No math calculations necessary. I did that for him (5 foot added to formula). Then I did it for different roller to water level distances if someone wanted.

Steve