I'd be careful trying to swim very far off and ocean shore. I was
surprized once while swimming in the surf how far the undertow(?)
carried me away. I had to swim hard to get back to the beach. Dumb
tourist.

I'm a freshwater boater myself but I've read that a boat rising and
falling on ocean swells can drag it's anchor if the line is too short.
When a storm hit our exposed moorings at a local freshwater sailing
club a lot of boats dragged their moorings and those were large
concrete blocks.

Wm Watt wrote:
I'd be careful trying to swim very far off and ocean shore. I was
surprized once while swimming in the surf how far the undertow(?)
carried me away. I had to swim hard to get back to the beach. Dumb
tourist.

I'm a freshwater boater myself but I've read that a boat rising and
falling on ocean swells can drag it's anchor if the line is too short.
When a storm hit our exposed moorings at a local freshwater sailing
club a lot of boats dragged their moorings and those were large
concrete blocks.

I've got a sit-on-top which would have all the flotation I need and I
just need to jump back on, but the canoe, though it floats when
swamped, I guess I would'n care to bail out.

The canoe I only use in the Intracoastal, of course.

Well, I went back to the store and thought the Danforth was too bulky
and sharp so I bought a 10lb Navy type anchor. It got the flukes, but
not the bulk.

http://www.basspro.com/servlet/catal...=SearchResults

Would I need a chain for it???

One situation I may encounter where I need a strong anchor is when I'm
facing a strong wind and the waves flood the boat too much, so I throw
anchor, bail out, and keep on going. This happens quite often in winter
time when I'm returning home. We are two people and one can't keep the
canoe straight into the wind.