Anchor line question

Buying a box anchor for my 25’ tritoon. It’ll weigh about 20 pounds. Putting 5’ of 3/8” chain on then the rope. How much rope to hold the boat. It’ll be on Tawakoni only. Pretty sure 100’ is fine in shallower water but need to know how much for 20-30’ water. I fish when the wind is 20 mph or less even when it’s whitecapping around 2 mile bridge but I don’t expect it to hold the boat when it’s rolling like that.

I’m thinking the min.sugested length is 3 to 1 but that may not be correct.
There is also a recommended chain length for different depths.

Someone in the know should be along.

Really depends on depth, wind, and currents. 3:1 if shallow and calm, upwards of 10:1 at the other extreme.

Thanks for the help. Ordered 3/8” x 200’ braided nylon.

This is why my next boat will have a spot lock. No more anchor chunking.

200' should be fine, but you will want 2 box anchors with that much rope. Set them in a "T" off the front, one anchor tied to each front corner of the toon with the toon pointing to the wind. This method holds toons great!



While spot lock is great in some instances, I did not like it for "anchoring" to fish for catfish. Sandbas/hybrid, even crappie...love spot lock.

3 to 1. If the deepest you'll ever fish is about 65 feet deep 200 feet will be plenty. Some may say more rope can be necessary. For me if the wind is that high I don't need to be anchoring anyway.

Good advice. Thank you all. I have spot lock but it won’t hold my toon in wind over 15mph depending on how far north I’m fishing on the lake.