Walt wrote:
donquijote1954 wrote:

I'm considering a heavy anchor (perhaps 6.5 lbs or heavier) such that
if --for example-- my partner gets tired in heavy wind I can have the
canoe stay put while she rests. Or if I must abandon the flooded canoe
and swim, I can come back and retrieve it at the same spot the next
day.

What do I need?

You want an anchor that holds, which is not necessarily the same thing
as a heavy anchor. There are lightweight anchors that hold quite well.
And heavy anchors that don't.

The primary determining factor is what sort of bottom you canoe over.
The characteristics of the bottom determine the optimum anchor. That
said, a basic small danforth should be fine for most situations.

Well, you seem to be right. I quote here...

Grapnel Type: This style of anchor works much like a
grappling hook. It takes hold of debris or rocks at the
bottom. It is ineffective on muddy or sandy bottoms but
works fairly well out at the jetties. Be prepared to loose
this anchor though.

On the other hand...

Danforth/Fortress type anchor: This type of anchor is
one of the best anchors for holding in many different
types of bottom composition. It weighs less than other
anchors yet holds better due to its design. These anchors
usually perform better when a short length of chain is
used as a leader before the rope is attached.

http://www.texasgulfcoastfishing.com/anchors.htm

Thanks. So I guess I'll go and exchange before it's too late.