I forget if I am right on this, please check me, but I seem to recall the as windage changes - the forces change by the cube, or something like that.

Force generated by speed is not linear.
force due to area is linear.
Does that make sense?

I have a 22lb delta plow anchor on my boat. It was oversized for my old boat and brought it over to the FW.

WaterMutt, its not my best day. See my spelling, today, for example.

Do you mean that increase the sail area by double and you increase the force on the anchor rode by double?

Maybe I am remembering loads by wind and conditions...

a 30' boat might need about 175 lbs. pull resistance for a lunch hook - 700 lbs. for a working/overnight anchor set-up - and 1,400 lbs. for a "storm" anchor set-up, or something like that.

Wind pressure, q, is proportional to the square of the wind velocity, V.

q ~ V times V. All recreational boats are low to the water, relative to the height of the atmosphere, so there isn't much change in wind pressure due to differing heights of recreational boats.

That would be correct, but if wind speed increases by two times, force on the anchor will increase four times.

Yes, a certain wind speed will double the "pull" if comparing two boats, one with half the available sail area.

If you are talking about the same boat but two different wind speeds, it isn't linear. What factor it does have, i am not sure.

Deep beat me to it.

i say set the whole thing up on a conveyor belt and test it properly.

I believe what you need is a "taper splice". I could never figure out how to do one, so I purchased my chain-rope in a package deal.

Some windlasses actually require a metric chain and rope, and when you buy the pre-spliced rode, you can sometimes have it made for a specific windlass.

If your windlass is supposed to use metric rode and you substitute a slightly different US size, I don't know if it will jamb or not.

What Seabuddy is described is called a Sentinel (or Kellet), and if you joined the Power Squadron, you'd know that...

After all these equations I think I'll just keep what I have

For what it's worth here is the info from Maxwell

Model RC500
Maximum Pull 227kg/500 lbs
Chain Short Link 6mm/7mm or 1/4"
Rope Size (Nylon) (8 plait recommended) 12mm
(3 strand or 8 plait) 1/2"


Oh yeah I forgot to mention when I sold my Crownline I had done my own splice with a flathead screwdriver and bic lighter. I hope they haven't lost their anchor

I like the Clorox bottle idea. Make sure it's rinsed real well as bleach aggressivelly attacks concrete.

Found a winner...

http://www.boatersland.com/lewhm30ht200px.html

I take it Maxwell chain and prespliced rode made specifically for your windlass was not an option.