I am at anchor in Vinyard Haven on Martha's Vineyard, MA. It is blowing hard and I seem to be anchored securely. The operative word is "seem".
So as the tide rises and falls and the wind changes direction, how can you look at your chartplotter (which I leave on all the time) and tell if you are still securely anchored? Less depth and your anchor plot will get larger. Wind or current can push you across the circle to the opposite side.
Here is my present chartplotter screen-
I have been here through multiple tide changes and wind and current changes.
The black wedge shape about 1 o'clock marks my current position. Have I been anchored securely? Am I still secure or have I dragged?
It can be hard to tell. How about trying to figure this question at 0100 after the wind picked up to 25+ kts?
So I created a visual aid. It is a piece of light window glass vinyl that has been printed with concentric circles. Like this-
I sewed a piece of Sunbrella to the edge for easy holding. Now to answer the important question of being secure or dragging, I just hold this against my chartplotter screen and see if I can align the partial circle segments to the same concentric circle. It helps if you have placed a mark on the screen where you dropped the anchor, but that is not mandatory.
So now I see the following-
You can adjust the chartplotter scale so that your circle segments are within the range of the concentric circles.
Above, clearly I am within the outer-most circle proving that I am still secure with my anchor holding. Quick and easy. Even at 0100 in the pouring rain.
I've been using this aid for several years and given copies to a couple of my sailing friends.
This ends my Show-and-Tell.
So as the tide rises and falls and the wind changes direction, how can you look at your chartplotter (which I leave on all the time) and tell if you are still securely anchored? Less depth and your anchor plot will get larger. Wind or current can push you across the circle to the opposite side.
Here is my present chartplotter screen-
I have been here through multiple tide changes and wind and current changes.
The black wedge shape about 1 o'clock marks my current position. Have I been anchored securely? Am I still secure or have I dragged?
It can be hard to tell. How about trying to figure this question at 0100 after the wind picked up to 25+ kts?
So I created a visual aid. It is a piece of light window glass vinyl that has been printed with concentric circles. Like this-
I sewed a piece of Sunbrella to the edge for easy holding. Now to answer the important question of being secure or dragging, I just hold this against my chartplotter screen and see if I can align the partial circle segments to the same concentric circle. It helps if you have placed a mark on the screen where you dropped the anchor, but that is not mandatory.
So now I see the following-
You can adjust the chartplotter scale so that your circle segments are within the range of the concentric circles.
Above, clearly I am within the outer-most circle proving that I am still secure with my anchor holding. Quick and easy. Even at 0100 in the pouring rain.
I've been using this aid for several years and given copies to a couple of my sailing friends.
This ends my Show-and-Tell.