Peter Island / Backwinded at anchor

Hello,

I have been reading a bit about being back winded at Peter. I have not been over there before and was curious what causes this. I am assuming it is the geography. Anyone want to send me a nice explanation?

On the same topic, what have others experienced while anchoring at Peter Island?

the wind changes direction? Where at Peter, there are several anchorages

Specifically Great Harbour and Little Harbour

I'm guessing this refers to the NE corner of Deadman's bay.

Topography can cause the wind to bend around headlands. Manchioneel bay on Cooper is a good example - boats are frequently pointing opposite to the prevailing wind (current plays a role too).

Basically whenever you anchor so that you don't have adequate depth through the whole swinging circle you need to be thinking of the possibility of backwinding.

You'll always be backwinded in Little Harbor. When I go there, and the weather is reasonably calm, I anchor just 'peeking out' at the channel close to the NE point (by the ruins of the Chubb house). You will avoid the backwinding effects of the high hills closer in.

You won't be backwinded in Great Harbor, either on the moorings or anchored along the southern shore, or the western shore towards Fisher Point. You could be backwinded if you anchor on the eastern shore, close in or towards Great Harbor Point.

Deadman's Bay isn't a great overnight anchorage in any weather, unless you're on a cat. On a mono, it's most often rolly.