I have been tying this hitch for some time, but do not know its name! I have been calling it my coaming hitch, because I use it mainly for securing the bitter end for tying loads on trucks, etc. It holds to a round anchor, as shown, far better than a clove hitch. In any case I don't often use a clove hitch for sailing, usually preferring the assurance of a bowline, halyard hitch or double figure-eight, etc.

I name this knot 'Ralph". Ralph is in fact a hitch, known as a Ground Line Hitch. "It is a tried and tested hitch that has been used by cod fishermen on their trawl nets and as a picket line hitch by horse soldiers and wilderness pioneers." , "and is suitable for all kinds of cordage or other pliable materials" So sayeth my copy of The Ultimate Encyclopedia of Knots and Ropework. G. Budworth.
Looks quite useful. If you really want it to stay, use a contrictor knot.....
To me it looks like a Midshipmans Hitch gone wrong. The M's H is a better knot I reckon, as I have just tried them both-- but maybe it is a fair dinkum knot.
Thanks Mega.. Googling confirms that it is indeed a Groundline Hitch.. and nothing like a Midshipmans Hitch.
So henceforce I shall call it Ralph !!