do you add extra lines to the bow ring and another to the stern ring, or do
you use the bow and stern dock lines on the boat?

One person launches like this:
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"I use the knot to attach a stainless steel carabiner to the line. When I
launch or retrieve the boat, I attach one carabiner and line to the bow
ring and another carabiner and line to a stern ring. I tie the end of the
stern line to the dock and then push the boat off the trailer into the
water while holding the bow ring line, which I walk over to the dock. That
way, it makes it easy for me to tie the boat to the dock while I move and
park the truck and trailer.

For retrieval, I tie the boat to the dock, back the trailer down into the
water, and pull the boat onto the trailer by hand with the bow line.

I use carabiners because they snap on better and a bit more elegantly than
snaps."
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This is an elegant sounding method, but it leaves me wondering what happens
to the line attached to the bow ring. Removing that while kneeling on the
bow could get pretty *hairy*.

As I'm always open to good ideas, I thought I'd present this and see if
anyone has a better way.