These are interesting......
http://www.spade-anchor.co.uk/
They even have drawings to print out to make paper models. Spent the afternoon making one up and it fitted great before I realised that the link on the page pointed to the wrong drawing!
I like the idea of a removable shank to make storing easier but they are very expensive. 200 quid for the galvie 10 kg.
Jim - thanks but it definately the pointy plow type that I am looking for.
Chris - Which size of delta anchor do you have?
On the old rib I remember once when I left a wave and saw the anchor float up out of the bow as the boat fell back to earth. Now lash the anchor down whenever it is in the boat. Thinking about a small triangular webbing net attached to the threads of the bow D ring to hold the whole lot down.
Bought a heap of rubber mats from B&Q today to line the locker.