Unexplained situation last night

[fred1diver]

Ok, so this to me is a bit mind blowing

we went out to anchor to see a local yearly fireworks competition hosted by our local casino last night, this is on the Ottawa river, so we drop anchor, there is decent current on the river, and we had some good winds.
So picture this:
We are at anchor, the bow is pointed into the current (yes the boat swings with the wind) but we go to sit at the bow to watch the show, I check the anchor rode, and it is going under the boat, as if the boat is moving up current (yes the engine is off)
As I said we did have wind, but enough to push the boat up current???
it was a first for us
My guests still cannot wrap their heads around this
The only thing ai can think of is there mig hr have been an eddy current as we were relatively close to a bridge piling (500 ft more or less)

 

[colemj]

Seems quite normal, and happens to us all the time in wind and current from different directions.

Mark

 

[Foswick]

Yeah, we see that all the time. It's kind of a problem because powerboaters plop down too close to sailboats, on the false assumption that everyone will swing together. But, it is not uncommon for us to be pointed and/or moving the opposite direction from everyone else.

Also, you might be right about a local back-current. We see that around here with tidal currents. You can see a stick floating by in one direction, while the boat is pulled the complete opposite direction, just a few feet away. I tend to think of a river as pretty homogeneously flowing in one direction, but I know it doesn't.

 

[dlochner]

The boat will lie to whatever force is stronger, wind or current. In your case the wind was having a greater effect on the boat than the current.

For fun, try setting an anchor when the wind and current are in opposition with equal force on the boat. The boat won't drift back or forward.

 

[Allan12210]

Happened all the time at China Beach State Park in San Francisco Bay. The hydrodynamic lift from the keel was larger than the wind force. We kept over riding our anchor rode. I had a 10 pound weight on the rode to supposedly allow the boat to cross over it when the tide shifted. Fast forward to 0600 with some one knocking on the hull. "Hey man, you are dragging your anchor". Only there wasn't one. Just a chafed through rode about 10 feet from the bow. Later I found a nice notch on the keel.

 

[odaydokay]

This has happened to me a few times. I’ve even had the anchor Road wrap around the keel. To keep this from happening, I tie a small mushroom anchor to the anchor Road to weight it down and it never hooked around the keel again.

 

[Stu Jackson]

Happened all the time at China Beach State Park in San Francisco Bay.

Me, too. It's where I learned to use a kellet. And I explained it to my friend John Reinman in his C36, but only after he'd had the same trouble. Wish you'd asked first... I learned about it from Latitude 38. They always said that was THE place to learn how to really anchor.

 

[dlochner]

The other solution, besides a kellet, is an all chain rode. The weight of the chain causes it to drop straight down allowing the boat to swing around the chain keeping the keel clear.